1216255615264 has 48 divisors (see below), whose sum is σ = 2455310919096. Its totient is φ = 592713676800.

The previous prime is 1216255615261. The next prime is 1216255615279. The reversal of 1216255615264 is 4625165526121.

It can be written as a sum of positive squares in 4 ways, for example, as 394861424400 + 821394190864 = 628380^2 + 906308^2 .

It is a super-2 number, since 2×1216255615264² (a number of 25 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1216255615261) 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, 885574 + ... + 1793530.

Almost surely, 2^{1216255615264} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1216255615264, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1227655459548).

1216255615264 is an abundant number, since it is smaller than the sum of its proper divisors (1239055303832).

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

1216255615264 is a wasteful number, since it uses less digits than its factorization.

1216255615264 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 909029 (or 909021 counting only the distinct ones).

The product of its digits is 864000, while the sum is 46.

The spelling of 1216255615264 in words is "one trillion, two hundred sixteen billion, two hundred fifty-five million, six hundred fifteen thousand, two hundred sixty-four".