21422928 has 40 divisors (see below), whose sum is σ = 55585728. Its totient is φ = 7109632.

The previous prime is 21422897. The next prime is 21422939. The reversal of 21422928 is 82922412.

It is a junction number, because it is equal to n+sod(n) for n = 21422895 and 21422904.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 11776 + ... + 13472.

Almost surely, 2^21422928 is an apocalyptic number.

It is an amenable number.

21422928 is an abundant number, since it is smaller than the sum of its proper divisors (34162800).

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

21422928 is a wasteful number, since it uses less digits than its factorization.

21422928 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1971 (or 1965 counting only the distinct ones).

The product of its digits is 4608, while the sum is 30.

The square root of 21422928 is about 4628.4908987704. The cubic root of 21422928 is about 277.7322266759.

The spelling of 21422928 in words is "twenty-one million, four hundred twenty-two thousand, nine hundred twenty-eight".