1200011220 has 48 divisors (see below), whose sum is σ = 3733369920. Its totient is φ = 320002848.

The previous prime is 1200011203. The next prime is 1200011233. The reversal of 1200011220 is 221100021.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1110582 + ... + 1111661.

It is an arithmetic number, because the mean of its divisors is an integer number (77778540).

Almost surely, 2^1200011220 is an apocalyptic number.

1200011220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1200011220 is an abundant number, since it is smaller than the sum of its proper divisors (2533358700).

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

1200011220 is a wasteful number, since it uses less digits than its factorization.

1200011220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2222261 (or 2222253 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 9.

The square root of 1200011220 is about 34641.1780977495. The cubic root of 1200011220 is about 1062.6618811248.

Adding to 1200011220 its reverse (221100021), we get a palindrome (1421111241).

It can be divided in two parts, 12000 and 11220, that added together give a triangular number (23220 = T₂₁₅).

The spelling of 1200011220 in words is "one billion, two hundred million, eleven thousand, two hundred twenty".