15651531540 has 72 divisors (see below), whose sum is σ = 47838799008. Its totient is φ = 4141874880.

The previous prime is 15651531461. The next prime is 15651531589. The reversal of 15651531540 is 4513515651.

15651531540 is a `hidden beast` number, since 1 + 5 + 65 + 1 + 53 + 1 + 540 = 666.

It is a super-2 number, since 2×15651531540² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 15651531495 and 15651531504.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 308302 + ... + 355461.

It is an arithmetic number, because the mean of its divisors is an integer number (664427764).

Almost surely, 2^15651531540 is an apocalyptic number.

15651531540 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

15651531540 is an abundant number, since it is smaller than the sum of its proper divisors (32187267468).

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

15651531540 is a wasteful number, since it uses less digits than its factorization.

15651531540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 663909 (or 663904 counting only the distinct ones).

The product of its (nonzero) digits is 45000, while the sum is 36.

The spelling of 15651531540 in words is "fifteen billion, six hundred fifty-one million, five hundred thirty-one thousand, five hundred forty".