21711725 has 12 divisors (see below), whose sum is σ = 30768864. Its totient is φ = 14887920.

The previous prime is 21711713. The next prime is 21711727. The reversal of 21711725 is 52711712.

It is not a de Polignac number, because 21711725 - 2⁴ = 21711709 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21711694 and 21711703.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21711727) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 61859 + ... + 62208.

It is an arithmetic number, because the mean of its divisors is an integer number (2564072).

Almost surely, 2^21711725 is an apocalyptic number.

21711725 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21711725 is a deficient number, since it is larger than the sum of its proper divisors (9057139).

21711725 is a wasteful number, since it uses less digits than its factorization.

21711725 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 124084 (or 124079 counting only the distinct ones).

The product of its digits is 980, while the sum is 26.

The square root of 21711725 is about 4659.5842089182. The cubic root of 21711725 is about 278.9746725723.

The spelling of 21711725 in words is "twenty-one million, seven hundred eleven thousand, seven hundred twenty-five".