20515239638 has 8 divisors (see below), whose sum is σ = 30773520840. Its totient is φ = 10257399360.

The previous prime is 20515239637. The next prime is 20515239707. The reversal of 20515239638 is 83693251502.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20515239637) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 56573 + ... + 210311.

It is an arithmetic number, because the mean of its divisors is an integer number (3846690105).

Almost surely, 2^20515239638 is an apocalyptic number.

20515239638 is a deficient number, since it is larger than the sum of its proper divisors (10258281202).

20515239638 is a wasteful number, since it uses less digits than its factorization.

20515239638 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 220462.

The product of its (nonzero) digits is 388800, while the sum is 44.

The spelling of 20515239638 in words is "twenty billion, five hundred fifteen million, two hundred thirty-nine thousand, six hundred thirty-eight".