25129681 has 2 divisors, whose sum is σ = 25129682. Its totient is φ = 25129680.

The previous prime is 25129667. The next prime is 25129691. The reversal of 25129681 is 18692152.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20250000 + 4879681 = 4500^2 + 2209^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-25129681 is a prime.

It is a super-2 number, since 2×25129681² = 1263001734323522, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (25129651) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12564840 + 12564841.

It is an arithmetic number, because the mean of its divisors is an integer number (12564841).

Almost surely, 2^25129681 is an apocalyptic number.

It is an amenable number.

25129681 is a deficient number, since it is larger than the sum of its proper divisors (1).

25129681 is an equidigital number, since it uses as much as digits as its factorization.

25129681 is an evil number, because the sum of its binary digits is even.

The product of its digits is 8640, while the sum is 34.

The square root of 25129681 is about 5012.9513263147. The cubic root of 25129681 is about 292.9064881922.

The spelling of 25129681 in words is "twenty-five million, one hundred twenty-nine thousand, six hundred eighty-one".