21693925 has 12 divisors (see below), whose sum is σ = 29346336. Its totient is φ = 15777200.

The previous prime is 21693911. The next prime is 21693937. The reversal of 21693925 is 52939612.

It is not a de Polignac number, because 21693925 - 2¹³ = 21685733 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 11 ways as a sum of consecutive naturals, for example, 39169 + ... + 39718.

It is an arithmetic number, because the mean of its divisors is an integer number (2445528).

Almost surely, 2^21693925 is an apocalyptic number.

21693925 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21693925 is a deficient number, since it is larger than the sum of its proper divisors (7652411).

21693925 is a wasteful number, since it uses less digits than its factorization.

21693925 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 78908 (or 78903 counting only the distinct ones).

The product of its digits is 29160, while the sum is 37.

The square root of 21693925 is about 4657.6737756095. The cubic root of 21693925 is about 278.8984141325.

The spelling of 21693925 in words is "twenty-one million, six hundred ninety-three thousand, nine hundred twenty-five".