25630991 has 2 divisors, whose sum is σ = 25630992. Its totient is φ = 25630990.

The previous prime is 25630987. The next prime is 25631029. The reversal of 25630991 is 19903652.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 25630991 - 2² = 25630987 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (25630921) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12815495 + 12815496.

It is an arithmetic number, because the mean of its divisors is an integer number (12815496).

Almost surely, 2^25630991 is an apocalyptic number.

25630991 is a deficient number, since it is larger than the sum of its proper divisors (1).

25630991 is an equidigital number, since it uses as much as digits as its factorization.

25630991 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 14580, while the sum is 35.

The square root of 25630991 is about 5062.7058970475. The cubic root of 25630991 is about 294.8414009116.

The spelling of 25630991 in words is "twenty-five million, six hundred thirty thousand, nine hundred ninety-one".