21139794732 has 96 divisors (see below), whose sum is σ = 57358551040. Its totient is φ = 5934539520.

The previous prime is 21139794721. The next prime is 21139794883. The reversal of 21139794732 is 23749793112.

It is a super-2 number, since 2×21139794732² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 6797994 + ... + 6801102.

Almost surely, 2^21139794732 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21139794732, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28679275520).

21139794732 is an abundant number, since it is smaller than the sum of its proper divisors (36218756308).

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

21139794732 is a wasteful number, since it uses less digits than its factorization.

21139794732 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4511 (or 4509 counting only the distinct ones).

The product of its digits is 571536, while the sum is 48.

It can be divided in two parts, 2113979 and 4732, that added together give a triangular number (2118711 = T₂₀₅₈).

The spelling of 21139794732 in words is "twenty-one billion, one hundred thirty-nine million, seven hundred ninety-four thousand, seven hundred thirty-two".