19929815929 has 9 divisors (see below), whose sum is σ = 20196587397. Its totient is φ = 19666528284.

The previous prime is 19929815909. The next prime is 19929815947. The reversal of 19929815929 is 92951892991.

The square root of 19929815929 is 141173.

It is a perfect power (a square), and thus also a powerful number.

It is a de Polignac number, because none of the positive numbers 2^k-19929815929 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19929815909) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 11151774 + ... + 11153560.

Almost surely, 2^19929815929 is an apocalyptic number.

19929815929 is the 141173-rd square number.

19929815929 is the 70587-th centered octagonal number.

It is an amenable number.

19929815929 is a deficient number, since it is larger than the sum of its proper divisors (266771468).

19929815929 is an frugal number, since it uses more digits than its factorization.

19929815929 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3732 (or 1866 counting only the distinct ones).

The product of its digits is 9447840, while the sum is 64.

Multiplying 19929815929 by its sum of digits (64), we get a square (1275508219456 = 1129384²).

The spelling of 19929815929 in words is "nineteen billion, nine hundred twenty-nine million, eight hundred fifteen thousand, nine hundred twenty-nine".