21106625 has 16 divisors (see below), whose sum is σ = 27730560. Its totient is φ = 15994800.

The previous prime is 21106607. The next prime is 21106643. The reversal of 21106625 is 52660112.

It is an interprime number because it is at equal distance from previous prime (21106607) and next prime (21106643).

It is not a de Polignac number, because 21106625 - 2⁸ = 21106369 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21106625.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2069 + ... + 6818.

It is an arithmetic number, because the mean of its divisors is an integer number (1733160).

Almost surely, 2^21106625 is an apocalyptic number.

21106625 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21106625 is a deficient number, since it is larger than the sum of its proper divisors (6623935).

21106625 is an equidigital number, since it uses as much as digits as its factorization.

21106625 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8921 (or 8911 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 23.

The square root of 21106625 is about 4594.1947063659. The cubic root of 21106625 is about 276.3585665562.

Adding to 21106625 its reverse (52660112), we get a palindrome (73766737).

The spelling of 21106625 in words is "twenty-one million, one hundred six thousand, six hundred twenty-five".