20394515621 has 8 divisors (see below), whose sum is σ = 21564184320. Its totient is φ = 19234474272.

The previous prime is 20394515573. The next prime is 20394515639. The reversal of 20394515621 is 12651549302.

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 20394515621 - 2³⁴ = 3214646437 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 (20394515821) 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, 2402480 + ... + 2410953.

It is an arithmetic number, because the mean of its divisors is an integer number (2695523040).

Almost surely, 2^20394515621 is an apocalyptic number.

It is an amenable number.

20394515621 is a deficient number, since it is larger than the sum of its proper divisors (1169668699).

20394515621 is a wasteful number, since it uses less digits than its factorization.

20394515621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4813675.

The product of its (nonzero) digits is 64800, while the sum is 38.

The spelling of 20394515621 in words is "twenty billion, three hundred ninety-four million, five hundred fifteen thousand, six hundred twenty-one".