21925497 has 16 divisors (see below), whose sum is σ = 32755392. Its totient is φ = 12928320.

The previous prime is 21925493. The next prime is 21925511. The reversal of 21925497 is 79452912.

It is not a de Polignac number, because 21925497 - 2² = 21925493 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21925493) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7758 + ... + 10199.

It is an arithmetic number, because the mean of its divisors is an integer number (2047212).

Almost surely, 2^21925497 is an apocalyptic number.

It is an amenable number.

21925497 is a deficient number, since it is larger than the sum of its proper divisors (10829895).

21925497 is a wasteful number, since it uses less digits than its factorization.

21925497 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18008.

The product of its digits is 45360, while the sum is 39.

The square root of 21925497 is about 4682.4669779935. The cubic root of 21925497 is about 279.8872717985.

It can be divided in two parts, 21925 and 497, that added together give a palindrome (22422).

The spelling of 21925497 in words is "twenty-one million, nine hundred twenty-five thousand, four hundred ninety-seven".