25905981 has 8 divisors (see below), whose sum is σ = 36043200. Its totient is φ = 16519712.

The previous prime is 25905941. The next prime is 25905991. The reversal of 25905981 is 18950952.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 25905981 - 2⁹ = 25905469 is a prime.

It is a super-2 number, since 2×25905981² = 1342239703144722, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25905941) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 187656 + ... + 187793.

It is an arithmetic number, because the mean of its divisors is an integer number (4505400).

Almost surely, 2^25905981 is an apocalyptic number.

It is an amenable number.

25905981 is a deficient number, since it is larger than the sum of its proper divisors (10137219).

25905981 is a wasteful number, since it uses less digits than its factorization.

25905981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 375475.

The product of its (nonzero) digits is 32400, while the sum is 39.

The square root of 25905981 is about 5089.7918425020. The cubic root of 25905981 is about 295.8920846263.

The spelling of 25905981 in words is "twenty-five million, nine hundred five thousand, nine hundred eighty-one".