25561618992 has 240 divisors, whose sum is σ = 92680456960. Its totient is φ = 6386646528.

The previous prime is 25561618991. The next prime is 25561618993. The reversal of 25561618992 is 29981616552.

25561618992 is a `hidden beast` number, since 2 + 5 + 5 + 616 + 18 + 9 + 9 + 2 = 666.

It is an interprime number because it is at equal distance from previous prime (25561618991) and next prime (25561618993).

It is not an unprimeable number, because it can be changed into a prime (25561618991) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 197643 + ... + 300309.

Almost surely, 2^25561618992 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 25561618992, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (46340228480).

25561618992 is an abundant number, since it is smaller than the sum of its proper divisors (67118837968).

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

25561618992 is a wasteful number, since it uses less digits than its factorization.

25561618992 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 102720 (or 102711 counting only the distinct ones).

The product of its digits is 2332800, while the sum is 54.

The spelling of 25561618992 in words is "twenty-five billion, five hundred sixty-one million, six hundred eighteen thousand, nine hundred ninety-two".