20931434329 has 27 divisors (see below), whose sum is σ = 23485545279. Its totient is φ = 18645971760.

The previous prime is 20931434323. The next prime is 20931434347. The reversal of 20931434329 is 92343413902.

It is a happy number.

The square root of 20931434329 is 144677.

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

It can be written as a sum of positive squares in only one way, i.e., 3096366025 + 17835068304 = 55645^2 + 133548^2 .

It is not a de Polignac number, because 20931434329 - 2¹⁷ = 20931303257 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20931434291 and 20931434300.

It is not an unprimeable number, because it can be changed into a prime (20931434323) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 58304652 + ... + 58305010.

Almost surely, 2^20931434329 is an apocalyptic number.

20931434329 is the 144677-th square number.

20931434329 is the 72339-th centered octagonal number.

It is an amenable number.

20931434329 is a deficient number, since it is larger than the sum of its proper divisors (2554110950).

20931434329 is an frugal number, since it uses more digits than its factorization.

20931434329 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 806 (or 403 counting only the distinct ones).

The product of its (nonzero) digits is 139968, while the sum is 40.

The spelling of 20931434329 in words is "twenty billion, nine hundred thirty-one million, four hundred thirty-four thousand, three hundred twenty-nine".