21900625 has 20 divisors (see below), whose sum is σ = 27828592. Its totient is φ = 17226000.

The previous prime is 21900583. The next prime is 21900649. The reversal of 21900625 is 52600912.

It is not a de Polignac number, because 21900625 - 2¹¹ = 21898577 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 21900625.

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 41614 + ... + 42136.

Almost surely, 2^21900625 is an apocalyptic number.

21900625 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21900625 is a deficient number, since it is larger than the sum of its proper divisors (5927967).

21900625 is an frugal number, since it uses more digits than its factorization.

21900625 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 610 (or 595 counting only the distinct ones).

The product of its (nonzero) digits is 1080, while the sum is 25.

The square root of 21900625 is about 4679.8103594056. The cubic root of 21900625 is about 279.7813982551.

The spelling of 21900625 in words is "twenty-one million, nine hundred thousand, six hundred twenty-five".