25990021518 has 32 divisors (see below), whose sum is σ = 53903256576. Its totient is φ = 8347351968.

The previous prime is 25990021493. The next prime is 25990021543. The reversal of 25990021518 is 81512009952.

It is an interprime number because it is at equal distance from previous prime (25990021493) and next prime (25990021543).

It is a super-2 number, since 2×25990021518² (a number of 22 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 25990021518.

It is a congruent number.

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, 545446 + ... + 591177.

It is an arithmetic number, because the mean of its divisors is an integer number (1684476768).

Almost surely, 2^25990021518 is an apocalyptic number.

25990021518 is an abundant number, since it is smaller than the sum of its proper divisors (27913235058).

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

25990021518 is a wasteful number, since it uses less digits than its factorization.

25990021518 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1136768.

The product of its (nonzero) digits is 64800, while the sum is 42.

The spelling of 25990021518 in words is "twenty-five billion, nine hundred ninety million, twenty-one thousand, five hundred eighteen".