25665801887961 has 48 divisors (see below), whose sum is σ = 40617283075200. Its totient is φ = 15544841485824.

The previous prime is 25665801887917. The next prime is 25665801887987. The reversal of 25665801887961 is 16978810856652.

25665801887961 is a `hidden beast` number, since 2 + 566 + 58 + 0 + 1 + 8 + 8 + 7 + 9 + 6 + 1 = 666.

It is not a de Polignac number, because 25665801887961 - 2⁶ = 25665801887897 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 25665801887961.

It is not an unprimeable number, because it can be changed into a prime (25665801887161) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 17112660 + ... + 18551946.

It is an arithmetic number, because the mean of its divisors is an integer number (846193397400).

Almost surely, 2^{25665801887961} is an apocalyptic number.

It is an amenable number.

25665801887961 is a deficient number, since it is larger than the sum of its proper divisors (14951481187239).

25665801887961 is a wasteful number, since it uses less digits than its factorization.

25665801887961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1443358 (or 1443355 counting only the distinct ones).

The product of its (nonzero) digits is 348364800, while the sum is 72.

The spelling of 25665801887961 in words is "twenty-five trillion, six hundred sixty-five billion, eight hundred one million, eight hundred eighty-seven thousand, nine hundred sixty-one".