25561645254 has 16 divisors (see below), whose sum is σ = 56803656240. Its totient is φ = 8520548400.

The previous prime is 25561645243. The next prime is 25561645261. The reversal of 25561645254 is 45254616552.

25561645254 is a `hidden beast` number, since 2 + 5 + 5 + 61 + 64 + 525 + 4 = 666.

It is a super-4 number, since 4×25561645254⁴ (a number of 43 digits) contains 4444 as substring.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 236681847 + ... + 236681954.

It is an arithmetic number, because the mean of its divisors is an integer number (3550228515).

Almost surely, 2^25561645254 is an apocalyptic number.

25561645254 is an abundant number, since it is smaller than the sum of its proper divisors (31242010986).

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

25561645254 is a wasteful number, since it uses less digits than its factorization.

25561645254 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 473363812 (or 473363806 counting only the distinct ones).

The product of its digits is 1440000, while the sum is 45.

The spelling of 25561645254 in words is "twenty-five billion, five hundred sixty-one million, six hundred forty-five thousand, two hundred fifty-four".