12515663540 has 12 divisors (see below), whose sum is σ = 26282893476. Its totient is φ = 5006265408.

The previous prime is 12515663533. The next prime is 12515663543. The reversal of 12515663540 is 4536651521.

It can be written as a sum of positive squares in 2 ways, for example, as 1291108624 + 11224554916 = 35932^2 + 105946^2 .

It is a junction number, because it is equal to n+sod(n) for n = 12515663494 and 12515663503.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12515663543) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 312891569 + ... + 312891608.

It is an arithmetic number, because the mean of its divisors is an integer number (2190241123).

Almost surely, 2^12515663540 is an apocalyptic number.

12515663540 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

12515663540 is an abundant number, since it is smaller than the sum of its proper divisors (13767229936).

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

12515663540 is a wasteful number, since it uses less digits than its factorization.

12515663540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 625783186 (or 625783184 counting only the distinct ones).

The product of its (nonzero) digits is 108000, while the sum is 38.

The spelling of 12515663540 in words is "twelve billion, five hundred fifteen million, six hundred sixty-three thousand, five hundred forty".