25661271571 has 16 divisors (see below), whose sum is σ = 29266876800. Its totient is φ = 22289338368.

The previous prime is 25661271533. The next prime is 25661271583. The reversal of 25661271571 is 17517216652.

It is a cyclic number.

It is not a de Polignac number, because 25661271571 - 2⁷ = 25661271443 is a prime.

It is a super-2 number, since 2×25661271571² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (25661271071) 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, 1469590 + ... + 1486948.

It is an arithmetic number, because the mean of its divisors is an integer number (1829179800).

Almost surely, 2^25661271571 is an apocalyptic number.

25661271571 is a deficient number, since it is larger than the sum of its proper divisors (3605605229).

25661271571 is a wasteful number, since it uses less digits than its factorization.

25661271571 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24078.

The product of its digits is 176400, while the sum is 43.

The spelling of 25661271571 in words is "twenty-five billion, six hundred sixty-one million, two hundred seventy-one thousand, five hundred seventy-one".