21752425 has 6 divisors (see below), whose sum is σ = 26973038. Its totient is φ = 17401920.

The previous prime is 21752383. The next prime is 21752429. The reversal of 21752425 is 52425712.

It can be written as a sum of positive squares in 3 ways, for example, as 6007401 + 15745024 = 2451^2 + 3968^2 .

It is not a de Polignac number, because 21752425 - 2⁹ = 21751913 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21752393 and 21752402.

It is not an unprimeable number, because it can be changed into a prime (21752429) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 435024 + ... + 435073.

Almost surely, 2^21752425 is an apocalyptic number.

21752425 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21752425 is a deficient number, since it is larger than the sum of its proper divisors (5220613).

21752425 is an equidigital number, since it uses as much as digits as its factorization.

21752425 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 870107 (or 870102 counting only the distinct ones).

The product of its digits is 5600, while the sum is 28.

The square root of 21752425 is about 4663.9495065877. The cubic root of 21752425 is about 279.1488823105.

The spelling of 21752425 in words is "twenty-one million, seven hundred fifty-two thousand, four hundred twenty-five".