21022525 has 12 divisors (see below), whose sum is σ = 26209012. Its totient is φ = 16727040.

The previous prime is 21022517. The next prime is 21022541. The reversal of 21022525 is 52522012.

It can be written as a sum of positive squares in 6 ways, for example, as 210681 + 20811844 = 459^2 + 4562^2 .

It is not a de Polignac number, because 21022525 - 2³ = 21022517 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2647 + ... + 7003.

Almost surely, 2^21022525 is an apocalyptic number.

21022525 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21022525 is a deficient number, since it is larger than the sum of its proper divisors (5186487).

21022525 is a wasteful number, since it uses less digits than its factorization.

21022525 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4560 (or 4555 counting only the distinct ones).

The product of its (nonzero) digits is 400, while the sum is 19.

The square root of 21022525 is about 4585.0327152595. The cubic root of 21022525 is about 275.9910248779.

Adding to 21022525 its reverse (52522012), we get a palindrome (73544537).

The spelling of 21022525 in words is "twenty-one million, twenty-two thousand, five hundred twenty-five".