1221133140 has 36 divisors (see below), whose sum is σ = 3704104404. Its totient is φ = 325635456.

The previous prime is 1221133139. The next prime is 1221133141. The reversal of 1221133140 is 413311221.

It is an interprime number because it is at equal distance from previous prime (1221133139) and next prime (1221133141).

It can be written as a sum of positive squares in 2 ways, for example, as 941507856 + 279625284 = 30684^2 + 16722^2 .

It is a tau number, because it is divible by the number of its divisors (36).

It is a super-2 number, since 2×1221133140² = 2982332291212519200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221133141) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3391857 + ... + 3392216.

It is an arithmetic number, because the mean of its divisors is an integer number (102891789).

Almost surely, 2^1221133140 is an apocalyptic number.

1221133140 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1221133140 is an abundant number, since it is smaller than the sum of its proper divisors (2482971264).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1221133140 is a wasteful number, since it uses less digits than its factorization.

1221133140 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6784088 (or 6784083 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

The square root of 1221133140 is about 34944.7154803126. The cubic root of 1221133140 is about 1068.8604457523.

Adding to 1221133140 its reverse (413311221), we get a palindrome (1634444361).

The spelling of 1221133140 in words is "one billion, two hundred twenty-one million, one hundred thirty-three thousand, one hundred forty".