21162625 has 16 divisors (see below), whose sum is σ = 28813824. Its totient is φ = 15390000.

The previous prime is 21162623. The next prime is 21162641. The reversal of 21162625 is 52626112.

It is not a de Polignac number, because 21162625 - 2¹ = 21162623 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (25).

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21162625.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21162623) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6321 + ... + 9070.

It is an arithmetic number, because the mean of its divisors is an integer number (1800864).

Almost surely, 2^21162625 is an apocalyptic number.

21162625 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21162625 is a deficient number, since it is larger than the sum of its proper divisors (7651199).

21162625 is a wasteful number, since it uses less digits than its factorization.

21162625 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15417 (or 15407 counting only the distinct ones).

The product of its digits is 1440, while the sum is 25.

The square root of 21162625 is about 4600.2853172385. The cubic root of 21162625 is about 276.6027618084.

Adding to 21162625 its reverse (52626112), we get a palindrome (73788737).

The spelling of 21162625 in words is "twenty-one million, one hundred sixty-two thousand, six hundred twenty-five".