25717639 has 2 divisors, whose sum is σ = 25717640. Its totient is φ = 25717638.

The previous prime is 25717609. The next prime is 25717649. The reversal of 25717639 is 93671752.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 25717639 - 2⁵ = 25717607 is a prime.

It is a super-2 number, since 2×25717639² = 1322793911468642, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (25717609) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12858819 + 12858820.

It is an arithmetic number, because the mean of its divisors is an integer number (12858820).

Almost surely, 2^25717639 is an apocalyptic number.

25717639 is a deficient number, since it is larger than the sum of its proper divisors (1).

25717639 is an equidigital number, since it uses as much as digits as its factorization.

25717639 is an evil number, because the sum of its binary digits is even.

The product of its digits is 79380, while the sum is 40.

The square root of 25717639 is about 5071.2561560229. The cubic root of 25717639 is about 295.1732736714.

The spelling of 25717639 in words is "twenty-five million, seven hundred seventeen thousand, six hundred thirty-nine".