25320857 has 4 divisors (see below), whose sum is σ = 26194020. Its totient is φ = 24447696.

The previous prime is 25320829. The next prime is 25320877. The reversal of 25320857 is 75802352.

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

It can be written as a sum of positive squares in 2 ways, for example, as 4426816 + 20894041 = 2104^2 + 4571^2 .

It is not a de Polignac number, because 25320857 - 2⁶ = 25320793 is a prime.

It is a super-2 number, since 2×25320857² = 1282291598428898, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (25320877) 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, 436538 + ... + 436595.

It is an arithmetic number, because the mean of its divisors is an integer number (6548505).

Almost surely, 2^25320857 is an apocalyptic number.

It is an amenable number.

25320857 is a deficient number, since it is larger than the sum of its proper divisors (873163).

25320857 is an equidigital number, since it uses as much as digits as its factorization.

25320857 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 873162.

The product of its (nonzero) digits is 16800, while the sum is 32.

The square root of 25320857 is about 5031.9834061730. The cubic root of 25320857 is about 293.6473821731.

The spelling of 25320857 in words is "twenty-five million, three hundred twenty thousand, eight hundred fifty-seven".