25646976561 has 16 divisors (see below), whose sum is σ = 34542787968. Its totient is φ = 16924656000.

The previous prime is 25646976541. The next prime is 25646976581. The reversal of 25646976561 is 16567964652.

It is an interprime number because it is at equal distance from previous prime (25646976541) and next prime (25646976581).

It is not a de Polignac number, because 25646976561 - 2¹⁷ = 25646845489 is a prime.

It is not an unprimeable number, because it can be changed into a prime (25646976541) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1788741 + ... + 1803021.

It is an arithmetic number, because the mean of its divisors is an integer number (2158924248).

Almost surely, 2^25646976561 is an apocalyptic number.

It is an amenable number.

25646976561 is a deficient number, since it is larger than the sum of its proper divisors (8895811407).

25646976561 is a wasteful number, since it uses less digits than its factorization.

25646976561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20312.

The product of its digits is 16329600, while the sum is 57.

The spelling of 25646976561 in words is "twenty-five billion, six hundred forty-six million, nine hundred seventy-six thousand, five hundred sixty-one".