21697932 has 12 divisors (see below), whose sum is σ = 50628536. Its totient is φ = 7232640.

The previous prime is 21697927. The next prime is 21697937. The reversal of 21697932 is 23979612.

It is an interprime number because it is at equal distance from previous prime (21697927) and next prime (21697937).

It is a tau number, because it is divible by the number of its divisors (12).

It is not an unprimeable number, because it can be changed into a prime (21697937) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 904069 + ... + 904092.

Almost surely, 2^21697932 is an apocalyptic number.

It is an amenable number.

21697932 is an abundant number, since it is smaller than the sum of its proper divisors (28930604).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21697932 is a wasteful number, since it uses less digits than its factorization.

21697932 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1808168 (or 1808166 counting only the distinct ones).

The product of its digits is 40824, while the sum is 39.

The square root of 21697932 is about 4658.1039060974. The cubic root of 21697932 is about 278.9155844870.

It can be divided in two parts, 2169 and 7932, that added together give a palindrome (10101).

The spelling of 21697932 in words is "twenty-one million, six hundred ninety-seven thousand, nine hundred thirty-two".