20947540239 has 12 divisors (see below), whose sum is σ = 30753584472. Its totient is φ = 13736091600.

The previous prime is 20947540219. The next prime is 20947540247. The reversal of 20947540239 is 93204574902.

20947540239 is a `hidden beast` number, since 209 + 4 + 7 + 5 + 402 + 39 = 666.

It is not a de Polignac number, because 20947540239 - 2²⁸ = 20679104783 is a prime.

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 20947540194 and 20947540203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20947540219) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 19077357 + ... + 19078454.

It is an arithmetic number, because the mean of its divisors is an integer number (2562798706).

Almost surely, 2^20947540239 is an apocalyptic number.

20947540239 is a deficient number, since it is larger than the sum of its proper divisors (9806044233).

20947540239 is a wasteful number, since it uses less digits than its factorization.

20947540239 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38155878 (or 38155875 counting only the distinct ones).

The product of its (nonzero) digits is 544320, while the sum is 45.

The spelling of 20947540239 in words is "twenty billion, nine hundred forty-seven million, five hundred forty thousand, two hundred thirty-nine".