21769625 has 8 divisors (see below), whose sum is σ = 27168648. Its totient is φ = 17415600.

The previous prime is 21769603. The next prime is 21769651. The reversal of 21769625 is 52696712.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 2968729 + 18800896 = 1723^2 + 4336^2 .

It is not a de Polignac number, because 21769625 - 2¹⁰ = 21768601 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 86954 + ... + 87203.

It is an arithmetic number, because the mean of its divisors is an integer number (3396081).

Almost surely, 2^21769625 is an apocalyptic number.

21769625 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21769625 is a deficient number, since it is larger than the sum of its proper divisors (5399023).

21769625 is an equidigital number, since it uses as much as digits as its factorization.

21769625 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 174172 (or 174162 counting only the distinct ones).

The product of its digits is 45360, while the sum is 38.

The square root of 21769625 is about 4665.7930729941. The cubic root of 21769625 is about 279.2224387964. Note that the first 3 decimals are identical.

The spelling of 21769625 in words is "twenty-one million, seven hundred sixty-nine thousand, six hundred twenty-five".