21386115072 has 432 divisors, whose sum is σ = 74597566680. Its totient is φ = 6103351296.

The previous prime is 21386115053. The next prime is 21386115103. The reversal of 21386115072 is 27051168312.

21386115072 is a `hidden beast` number, since 2 + 1 + 38 + 611 + 5 + 0 + 7 + 2 = 666.

It is a tau number, because it is divible by the number of its divisors (432).

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 24385098 + ... + 24385974.

Almost surely, 2^21386115072 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 21386115072, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37298783340).

21386115072 is an abundant number, since it is smaller than the sum of its proper divisors (53211451608).

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

21386115072 is an frugal number, since it uses more digits than its factorization.

21386115072 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 928 (or 889 counting only the distinct ones).

The product of its (nonzero) digits is 20160, while the sum is 36.

The spelling of 21386115072 in words is "twenty-one billion, three hundred eighty-six million, one hundred fifteen thousand, seventy-two".