21382645021 has 8 divisors (see below), whose sum is σ = 21413096960. Its totient is φ = 21352217328.

The previous prime is 21382645019. The next prime is 21382645069. The reversal of 21382645021 is 12054628312.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21382645021 - 2¹ = 21382645019 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21382645001) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2369500 + ... + 2378506.

It is an arithmetic number, because the mean of its divisors is an integer number (2676637120).

Almost surely, 2^21382645021 is an apocalyptic number.

It is an amenable number.

21382645021 is a deficient number, since it is larger than the sum of its proper divisors (30451939).

21382645021 is a wasteful number, since it uses less digits than its factorization.

21382645021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12123.

The product of its (nonzero) digits is 23040, while the sum is 34.

The spelling of 21382645021 in words is "twenty-one billion, three hundred eighty-two million, six hundred forty-five thousand, twenty-one".