21123792 has 60 divisors (see below), whose sum is σ = 62602020. Its totient is φ = 6626304.

The previous prime is 21123779. The next prime is 21123841. The reversal of 21123792 is 29732112.

It can be written as a sum of positive squares in 2 ways, for example, as 16353936 + 4769856 = 4044^2 + 2184^2 .

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, 1867 + ... + 6762.

It is an arithmetic number, because the mean of its divisors is an integer number (1043367).

Almost surely, 2^21123792 is an apocalyptic number.

It is an amenable number.

21123792 is an abundant number, since it is smaller than the sum of its proper divisors (41478228).

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

21123792 is a wasteful number, since it uses less digits than its factorization.

21123792 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8660 (or 8651 counting only the distinct ones).

The product of its digits is 1512, while the sum is 27.

The square root of 21123792 is about 4596.0626627582. The cubic root of 21123792 is about 276.4334713449.

The spelling of 21123792 in words is "twenty-one million, one hundred twenty-three thousand, seven hundred ninety-two".