21522025 has 18 divisors (see below), whose sum is σ = 31046190. Its totient is φ = 14757120.

The previous prime is 21522001. The next prime is 21522037. The reversal of 21522025 is 52022512.

It can be written as a sum of positive squares in 3 ways, for example, as 112896 + 21409129 = 336^2 + 4627^2 .

It is not a de Polignac number, because 21522025 - 2¹⁵ = 21489257 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21521993 and 21522011.

It is an unprimeable number.

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 17 ways as a sum of consecutive naturals, for example, 7560 + ... + 10009.

Almost surely, 2^21522025 is an apocalyptic number.

21522025 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21522025 is a deficient number, since it is larger than the sum of its proper divisors (9524165).

21522025 is a wasteful number, since it uses less digits than its factorization.

21522025 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17593 (or 17581 counting only the distinct ones).

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

The square root of 21522025 is about 4639.1836566362. The cubic root of 21522025 is about 278.1598075361.

Adding to 21522025 its reverse (52022512), we get a palindrome (73544537).

The spelling of 21522025 in words is "twenty-one million, five hundred twenty-two thousand, twenty-five".