21502434621 has 8 divisors (see below), whose sum is σ = 28992047040. Its totient is φ = 14173889312.

The previous prime is 21502434593. The next prime is 21502434659. The reversal of 21502434621 is 12643420512.

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 21502434621 - 2⁷ = 21502434493 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21502434661) 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, 40266465 + ... + 40266998.

It is an arithmetic number, because the mean of its divisors is an integer number (3624005880).

Almost surely, 2^21502434621 is an apocalyptic number.

It is an amenable number.

21502434621 is a deficient number, since it is larger than the sum of its proper divisors (7489612419).

21502434621 is an equidigital number, since it uses as much as digits as its factorization.

21502434621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 80533555.

The product of its (nonzero) digits is 11520, while the sum is 30.

The spelling of 21502434621 in words is "twenty-one billion, five hundred two million, four hundred thirty-four thousand, six hundred twenty-one".