25378661536 has 12 divisors (see below), whose sum is σ = 49964239962. Its totient is φ = 12689330752.

The previous prime is 25378661501. The next prime is 25378661579. The reversal of 25378661536 is 63516687352.

It can be written as a sum of positive squares in only one way, i.e., 24006403600 + 1372257936 = 154940^2 + 37044^2 .

It is a super-2 number, since 2×25378661536² (a number of 22 digits) contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 396541555 + ... + 396541618.

Almost surely, 2^25378661536 is an apocalyptic number.

It is an amenable number.

25378661536 is a deficient number, since it is larger than the sum of its proper divisors (24585578426).

25378661536 is an equidigital number, since it uses as much as digits as its factorization.

25378661536 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 793083183 (or 793083175 counting only the distinct ones).

The product of its digits is 5443200, while the sum is 52.

The spelling of 25378661536 in words is "twenty-five billion, three hundred seventy-eight million, six hundred sixty-one thousand, five hundred thirty-six".