25643530 has 24 divisors (see below), whose sum is σ = 50738436. Its totient is φ = 9324480.

The previous prime is 25643507. The next prime is 25643533. The reversal of 25643530 is 3534652.

It can be written as a sum of positive squares in 2 ways, for example, as 22268961 + 3374569 = 4719^2 + 1837^2 .

It is not an unprimeable number, because it can be changed into a prime (25643533) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 9387 + ... + 11806.

Almost surely, 2^25643530 is an apocalyptic number.

25643530 is a deficient number, since it is larger than the sum of its proper divisors (25094906).

25643530 is a wasteful number, since it uses less digits than its factorization.

25643530 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21222 (or 21211 counting only the distinct ones).

The product of its (nonzero) digits is 10800, while the sum is 28.

The square root of 25643530 is about 5063.9441150155. The cubic root of 25643530 is about 294.8894731017.

The spelling of 25643530 in words is "twenty-five million, six hundred forty-three thousand, five hundred thirty".