21387632025072 has 80 divisors (see below), whose sum is σ = 57184171566080. Its totient is φ = 6881032166400.

The previous prime is 21387632025049. The next prime is 21387632025077. The reversal of 21387632025072 is 27052023678312.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21387632025077) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 18398329 + ... + 19526232.

It is an arithmetic number, because the mean of its divisors is an integer number (714802144576).

Almost surely, 2^{21387632025072} is an apocalyptic number.

It is an amenable number.

21387632025072 is an abundant number, since it is smaller than the sum of its proper divisors (35796539541008).

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

21387632025072 is a wasteful number, since it uses less digits than its factorization.

21387632025072 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37924982 (or 37924976 counting only the distinct ones).

The product of its (nonzero) digits is 1693440, while the sum is 48.

The spelling of 21387632025072 in words is "twenty-one trillion, three hundred eighty-seven billion, six hundred thirty-two million, twenty-five thousand, seventy-two".