20315257515 has 32 divisors (see below), whose sum is σ = 41275445760. Its totient is φ = 9286974432.

The previous prime is 20315257489. The next prime is 20315257517. The reversal of 20315257515 is 51575251302.

20315257515 is a `hidden beast` number, since 2 + 0 + 31 + 52 + 575 + 1 + 5 = 666.

It is not a de Polignac number, because 20315257515 - 2¹⁵ = 20315224747 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20315257515.

It is not an unprimeable number, because it can be changed into a prime (20315257517) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 10747869 + ... + 10749758.

It is an arithmetic number, because the mean of its divisors is an integer number (1289857680).

Almost surely, 2^20315257515 is an apocalyptic number.

20315257515 is an abundant number, since it is smaller than the sum of its proper divisors (20960188245).

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

20315257515 is a wasteful number, since it uses less digits than its factorization.

20315257515 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21497648 (or 21497642 counting only the distinct ones).

The product of its (nonzero) digits is 52500, while the sum is 36.

The spelling of 20315257515 in words is "twenty billion, three hundred fifteen million, two hundred fifty-seven thousand, five hundred fifteen".