1215518864 has 40 divisors (see below), whose sum is σ = 2729432448. Its totient is φ = 513596160.

The previous prime is 1215518861. The next prime is 1215518893. The reversal of 1215518864 is 4688155121.

It is a super-2 number, since 2×1215518864² = 2954972217479700992, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1215518861) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 68477 + ... + 84380.

Almost surely, 2^1215518864 is an apocalyptic number.

1215518864 is a gapful number since it is divisible by the number (14) formed by its first and last digit.

It is an amenable number.

1215518864 is an abundant number, since it is smaller than the sum of its proper divisors (1513913584).

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

1215518864 is a wasteful number, since it uses less digits than its factorization.

1215518864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 152943 (or 152937 counting only the distinct ones).

The product of its digits is 76800, while the sum is 41.

The square root of 1215518864 is about 34864.2921052472. The cubic root of 1215518864 is about 1067.2198663460.

The spelling of 1215518864 in words is "one billion, two hundred fifteen million, five hundred eighteen thousand, eight hundred sixty-four".