1221112520 has 64 divisors (see below), whose sum is σ = 2935396800. Its totient is φ = 455811840.

The previous prime is 1221112489. The next prime is 1221112531. The reversal of 1221112520 is 252111221.

It is a super-2 number, since 2×1221112520² = 2982231573001500800, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 38930 + ... + 62910.

It is an arithmetic number, because the mean of its divisors is an integer number (45865575).

Almost surely, 2^1221112520 is an apocalyptic number.

1221112520 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1221112520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1467698400).

1221112520 is an abundant number, since it is smaller than the sum of its proper divisors (1714284280).

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

1221112520 is a wasteful number, since it uses less digits than its factorization.

1221112520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24078 (or 24074 counting only the distinct ones).

The product of its (nonzero) digits is 80, while the sum is 17.

The square root of 1221112520 is about 34944.4204416098. The cubic root of 1221112520 is about 1068.8544294751.

Adding to 1221112520 its reverse (252111221), we get a palindrome (1473223741).

The spelling of 1221112520 in words is "one billion, two hundred twenty-one million, one hundred twelve thousand, five hundred twenty".