21985475625 has 75 divisors (see below), whose sum is σ = 41102359441. Its totient is φ = 11707794000.

The previous prime is 21985475579. The next prime is 21985475639. The reversal of 21985475625 is 52657458912.

The square root of 21985475625 is 148275.

It is a perfect power (a square), and thus also a powerful number.

21985475625 is a `hidden beast` number, since 2 + 1 + 9 + 8 + 5 + 4 + 7 + 5 + 625 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 1723661289 + 20261814336 = 41517^2 + 142344^2 .

It is a tau number, because it is divible by the number of its divisors (75).

It is not a de Polignac number, because 21985475625 - 2²⁵ = 21951921193 is a prime.

It is a super-2 number, since 2×21985475625² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

Its product of digits (6048000) is a multiple of the sum of its prime factors (1350).

It is an unprimeable number.

It is a polite number, since it can be written in 74 ways as a sum of consecutive naturals, for example, 33361546 + ... + 33362204.

Almost surely, 2^21985475625 is an apocalyptic number.

21985475625 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21985475625 is the 148275-th square number.

21985475625 is the 74138-th centered octagonal number.

It is an amenable number.

21985475625 is a deficient number, since it is larger than the sum of its proper divisors (19116883816).

21985475625 is an frugal number, since it uses more digits than its factorization.

21985475625 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1350 (or 667 counting only the distinct ones).

The product of its digits is 6048000, while the sum is 54.

The spelling of 21985475625 in words is "twenty-one billion, nine hundred eighty-five million, four hundred seventy-five thousand, six hundred twenty-five".