1221133120 has 56 divisors (see below), whose sum is σ = 3078885384. Its totient is φ = 459718656.

The previous prime is 1221133117. The next prime is 1221133139. The reversal of 1221133120 is 213311221.

It can be written as a sum of positive squares in 4 ways, for example, as 280361536 + 940771584 = 16744^2 + 30672^2 .

It is a Harshad number since it is a multiple of its sum of digits (16).

It is a junction number, because it is equal to n+sod(n) for n = 1221133094 and 1221133103.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 106797 + ... + 117676.

Almost surely, 2^1221133120 is an apocalyptic number.

1221133120 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1221133120 is an abundant number, since it is smaller than the sum of its proper divisors (1857752264).

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

1221133120 is a wasteful number, since it uses less digits than its factorization.

1221133120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 224507 (or 224497 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 16.

The square root of 1221133120 is about 34944.7151941463. The cubic root of 1221133120 is about 1068.8604399170.

Adding to 1221133120 its reverse (213311221), we get a palindrome (1434444341).

The spelling of 1221133120 in words is "one billion, two hundred twenty-one million, one hundred thirty-three thousand, one hundred twenty".