25002561 has 4 divisors (see below), whose sum is σ = 33336752. Its totient is φ = 16668372.

The previous prime is 25002557. The next prime is 25002599. The reversal of 25002561 is 16520052.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 25002561 - 2² = 25002557 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (25002511) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4167091 + ... + 4167096.

It is an arithmetic number, because the mean of its divisors is an integer number (8334188).

Almost surely, 2^25002561 is an apocalyptic number.

It is an amenable number.

25002561 is a deficient number, since it is larger than the sum of its proper divisors (8334191).

25002561 is an equidigital number, since it uses as much as digits as its factorization.

25002561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8334190.

The product of its (nonzero) digits is 600, while the sum is 21.

The square root of 25002561 is about 5000.2560934416. The cubic root of 25002561 is about 292.4117580263.

The spelling of 25002561 in words is "twenty-five million, two thousand, five hundred sixty-one".