21020873238 has 12 divisors (see below), whose sum is σ = 45545225388. Its totient is φ = 7006957740.

The previous prime is 21020873221. The next prime is 21020873257. The reversal of 21020873238 is 83237802012.

It is a happy number.

21020873238 is a `hidden beast` number, since 210 + 208 + 7 + 3 + 238 = 666.

It is a super-2 number, since 2×21020873238² (a number of 21 digits) contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 583913128 + ... + 583913163.

It is an arithmetic number, because the mean of its divisors is an integer number (3795435449).

Almost surely, 2^21020873238 is an apocalyptic number.

21020873238 is an abundant number, since it is smaller than the sum of its proper divisors (24524352150).

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

21020873238 is a wasteful number, since it uses less digits than its factorization.

21020873238 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1167826299 (or 1167826296 counting only the distinct ones).

The product of its (nonzero) digits is 32256, while the sum is 36.

The spelling of 21020873238 in words is "twenty-one billion, twenty million, eight hundred seventy-three thousand, two hundred thirty-eight".