21662025 has 96 divisors (see below), whose sum is σ = 46473216. Its totient is φ = 8712000.

The previous prime is 21661999. The next prime is 21662041. The reversal of 21662025 is 52026612.

It is not a de Polignac number, because 21662025 - 2⁵ = 21661993 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21661986 and 21662004.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 698760 + ... + 698790.

It is an arithmetic number, because the mean of its divisors is an integer number (484096).

Almost surely, 2^21662025 is an apocalyptic number.

21662025 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21662025 is an abundant number, since it is smaller than the sum of its proper divisors (24811191).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21662025 is a wasteful number, since it uses less digits than its factorization.

21662025 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 84 (or 57 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 24.

The square root of 21662025 is about 4654.2480595688. The cubic root of 21662025 is about 278.7616442950.

Adding to 21662025 its reverse (52026612), we get a palindrome (73688637).

The spelling of 21662025 in words is "twenty-one million, six hundred sixty-two thousand, twenty-five".