21397192 has 48 divisors (see below), whose sum is σ = 43891200. Its totient is φ = 9767520.

The previous prime is 21397171. The next prime is 21397217. The reversal of 21397192 is 29179312.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 89409 + ... + 89647.

It is an arithmetic number, because the mean of its divisors is an integer number (914400).

Almost surely, 2^21397192 is an apocalyptic number.

It is an amenable number.

21397192 is an abundant number, since it is smaller than the sum of its proper divisors (22494008).

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

21397192 is a wasteful number, since it uses less digits than its factorization.

21397192 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 314 (or 291 counting only the distinct ones).

The product of its digits is 6804, while the sum is 34.

The square root of 21397192 is about 4625.7098914653. The cubic root of 21397192 is about 277.6209661182.

The spelling of 21397192 in words is "twenty-one million, three hundred ninety-seven thousand, one hundred ninety-two".