21383123472 has 80 divisors (see below), whose sum is σ = 63036382080. Its totient is φ = 6935061888.

The previous prime is 21383123459. The next prime is 21383123479. The reversal of 21383123472 is 27432138312.

21383123472 is a `hidden beast` number, since 2 + 138 + 31 + 23 + 472 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (21383123479) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 652908 + ... + 684875.

It is an arithmetic number, because the mean of its divisors is an integer number (787954776).

Almost surely, 2^21383123472 is an apocalyptic number.

It is an amenable number.

21383123472 is an abundant number, since it is smaller than the sum of its proper divisors (41653258608).

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

21383123472 is a wasteful number, since it uses less digits than its factorization.

21383123472 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1337837 (or 1337825 counting only the distinct ones).

The product of its digits is 48384, while the sum is 36.

The spelling of 21383123472 in words is "twenty-one billion, three hundred eighty-three million, one hundred twenty-three thousand, four hundred seventy-two".