25640939 has 2 divisors, whose sum is σ = 25640940. Its totient is φ = 25640938.

The previous prime is 25640933. The next prime is 25640957. The reversal of 25640939 is 93904652.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 25640939 - 2⁸ = 25640683 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (25640933) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12820469 + 12820470.

It is an arithmetic number, because the mean of its divisors is an integer number (12820470).

Almost surely, 2^25640939 is an apocalyptic number.

25640939 is a deficient number, since it is larger than the sum of its proper divisors (1).

25640939 is an equidigital number, since it uses as much as digits as its factorization.

25640939 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 58320, while the sum is 38.

The square root of 25640939 is about 5063.6882802953. The cubic root of 25640939 is about 294.8795409751.

The spelling of 25640939 in words is "twenty-five million, six hundred forty thousand, nine hundred thirty-nine".