21711925 has 12 divisors (see below), whose sum is σ = 27069696. Its totient is φ = 17274800.

The previous prime is 21711917. The next prime is 21711959. The reversal of 21711925 is 52911712.

It is not a de Polignac number, because 21711925 - 2³ = 21711917 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21711893 and 21711902.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2502 + ... + 7048.

It is an arithmetic number, because the mean of its divisors is an integer number (2255808).

Almost surely, 2^21711925 is an apocalyptic number.

21711925 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21711925 is a deficient number, since it is larger than the sum of its proper divisors (5357771).

21711925 is a wasteful number, since it uses less digits than its factorization.

21711925 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4748 (or 4743 counting only the distinct ones).

The product of its digits is 1260, while the sum is 28.

The square root of 21711925 is about 4659.6056700111. The cubic root of 21711925 is about 278.9755291719.

It can be divided in two parts, 2171 and 1925, that added together give a 12-th power (4096 = 2¹²).

The spelling of 21711925 in words is "twenty-one million, seven hundred eleven thousand, nine hundred twenty-five".