25671681 has 16 divisors (see below), whose sum is σ = 43465600. Its totient is φ = 14669424.

The previous prime is 25671671. The next prime is 25671713. The reversal of 25671681 is 18617652.

25671681 is a `hidden beast` number, since 2 + 567 + 16 + 81 = 666.

It is not a de Polignac number, because 25671681 - 2⁷ = 25671553 is a prime.

It is a super-2 number, since 2×25671681² = 1318070410731522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (25671601) 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, 67726 + ... + 68103.

It is an arithmetic number, because the mean of its divisors is an integer number (2716600).

Almost surely, 2^25671681 is an apocalyptic number.

25671681 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

25671681 is a deficient number, since it is larger than the sum of its proper divisors (17793919).

25671681 is a wasteful number, since it uses less digits than its factorization.

25671681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 135845 (or 135839 counting only the distinct ones).

The product of its digits is 20160, while the sum is 36.

The square root of 25671681 is about 5066.7229053896. The cubic root of 25671681 is about 294.9973417361.

The spelling of 25671681 in words is "twenty-five million, six hundred seventy-one thousand, six hundred eighty-one".