25390639 has 4 divisors (see below), whose sum is σ = 26884224. Its totient is φ = 23897056.

The previous prime is 25390637. The next prime is 25390649. The reversal of 25390639 is 93609352.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 25390639 - 2¹ = 25390637 is a prime.

It is a super-3 number, since 3×25390639³ (a number of 23 digits) contains 333 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 25390598 and 25390607.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25390637) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 746767 + ... + 746800.

It is an arithmetic number, because the mean of its divisors is an integer number (6721056).

Almost surely, 2^25390639 is an apocalyptic number.

25390639 is a deficient number, since it is larger than the sum of its proper divisors (1493585).

25390639 is a wasteful number, since it uses less digits than its factorization.

25390639 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1493584.

The product of its (nonzero) digits is 43740, while the sum is 37.

The square root of 25390639 is about 5038.9124818754. The cubic root of 25390639 is about 293.9168899855.

The spelling of 25390639 in words is "twenty-five million, three hundred ninety thousand, six hundred thirty-nine".