1215532920 has 64 divisors (see below), whose sum is σ = 4167544320. Its totient is φ = 277835904.

The previous prime is 1215532919. The next prime is 1215532921. The reversal of 1215532920 is 292355121.

It is an interprime number because it is at equal distance from previous prime (1215532919) and next prime (1215532921).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1215532921) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 722692 + ... + 724371.

It is an arithmetic number, because the mean of its divisors is an integer number (65117880).

Almost surely, 2^1215532920 is an apocalyptic number.

1215532920 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1215532920 is an abundant number, since it is smaller than the sum of its proper divisors (2952011400).

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

1215532920 is a wasteful number, since it uses less digits than its factorization.

1215532920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1447084 (or 1447080 counting only the distinct ones).

The product of its (nonzero) digits is 5400, while the sum is 30.

The square root of 1215532920 is about 34864.4936862706. The cubic root of 1215532920 is about 1067.2239800308.

The spelling of 1215532920 in words is "one billion, two hundred fifteen million, five hundred thirty-two thousand, nine hundred twenty".