21404685072 has 160 divisors (see below), whose sum is σ = 58217829376. Its totient is φ = 6768230400.

The previous prime is 21404685061. The next prime is 21404685073. The reversal of 21404685072 is 27058640412.

It is a self number, because there is not a number n which added to its sum of digits gives 21404685072.

It is not an unprimeable number, because it can be changed into a prime (21404685073) by changing a digit.

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, 20963922 + ... + 20964942.

Almost surely, 2^21404685072 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 21404685072, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29108914688).

21404685072 is an abundant number, since it is smaller than the sum of its proper divisors (36813144304).

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

21404685072 is a wasteful number, since it uses less digits than its factorization.

21404685072 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1329 (or 1323 counting only the distinct ones).

The product of its (nonzero) digits is 107520, while the sum is 39.

The spelling of 21404685072 in words is "twenty-one billion, four hundred four million, six hundred eighty-five thousand, seventy-two".