21051779224 has 16 divisors (see below), whose sum is σ = 45110955600. Its totient is φ = 9022191072.

The previous prime is 21051779219. The next prime is 21051779233. The reversal of 21051779224 is 42297715012.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 187962259 + ... + 187962370.

It is an arithmetic number, because the mean of its divisors is an integer number (2819434725).

Almost surely, 2^21051779224 is an apocalyptic number.

It is an amenable number.

21051779224 is an abundant number, since it is smaller than the sum of its proper divisors (24059176376).

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

21051779224 is a wasteful number, since it uses less digits than its factorization.

21051779224 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 375924642 (or 375924638 counting only the distinct ones).

The product of its (nonzero) digits is 70560, while the sum is 40.

The spelling of 21051779224 in words is "twenty-one billion, fifty-one million, seven hundred seventy-nine thousand, two hundred twenty-four".