25570521 has 12 divisors (see below), whose sum is σ = 37021972. Its totient is φ = 17006976.

The previous prime is 25570487. The next prime is 25570537. The reversal of 25570521 is 12507552.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 20575296 + 4995225 = 4536^2 + 2235^2 .

It is not a de Polignac number, because 25570521 - 2¹⁵ = 25537753 is a prime.

It is a super-2 number, since 2×25570521² = 1307703088422882, which contains 22 as substring.

It is a Duffinian number.

It is a plaindrome in base 14.

It is not an unprimeable number, because it can be changed into a prime (25570591) 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, 1005 + ... + 7221.

Almost surely, 2^25570521 is an apocalyptic number.

It is an amenable number.

25570521 is a deficient number, since it is larger than the sum of its proper divisors (11451451).

25570521 is a wasteful number, since it uses less digits than its factorization.

25570521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6680 (or 6677 counting only the distinct ones).

The product of its (nonzero) digits is 3500, while the sum is 27.

The square root of 25570521 is about 5056.7302676730. The cubic root of 25570521 is about 294.6093498110.

The spelling of 25570521 in words is "twenty-five million, five hundred seventy thousand, five hundred twenty-one".