25643291 has 2 divisors, whose sum is σ = 25643292. Its totient is φ = 25643290.

The previous prime is 25643263. The next prime is 25643297. The reversal of 25643291 is 19234652.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 25643291 - 2⁶ = 25643227 is a prime.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (25643297) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12821645 + 12821646.

It is an arithmetic number, because the mean of its divisors is an integer number (12821646).

Almost surely, 2^25643291 is an apocalyptic number.

25643291 is a deficient number, since it is larger than the sum of its proper divisors (1).

25643291 is an equidigital number, since it uses as much as digits as its factorization.

25643291 is an evil number, because the sum of its binary digits is even.

The product of its digits is 12960, while the sum is 32.

The square root of 25643291 is about 5063.9205167538. The cubic root of 25643291 is about 294.8885569667. Note that the first 3 decimals are identical.

The spelling of 25643291 in words is "twenty-five million, six hundred forty-three thousand, two hundred ninety-one".