25567729656 has 128 divisors (see below), whose sum is σ = 75628615680. Its totient is φ = 7051539456.

The previous prime is 25567729651. The next prime is 25567729721. The reversal of 25567729656 is 65692776552.

It is a Smith number, since the sum of its digits (60) coincides with the sum of the digits of its prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 25567729656.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25567729651) 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 31 ways as a sum of consecutive naturals, for example, 554230 + ... + 598586.

It is an arithmetic number, because the mean of its divisors is an integer number (590848560).

Almost surely, 2^25567729656 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 25567729656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37814307840).

25567729656 is an abundant number, since it is smaller than the sum of its proper divisors (50060886024).

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

25567729656 is a wasteful number, since it uses less digits than its factorization.

25567729656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44493 (or 44489 counting only the distinct ones).

The product of its digits is 47628000, while the sum is 60.

The spelling of 25567729656 in words is "twenty-five billion, five hundred sixty-seven million, seven hundred twenty-nine thousand, six hundred fifty-six".