20713394132809 has 27 divisors (see below), whose sum is σ = 24155322180327. Its totient is φ = 17710127500464.

The previous prime is 20713394132791. The next prime is 20713394132861. The reversal of 20713394132809 is 90823149331702.

The square root of 20713394132809 is 4551197.

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., 20263727325625 + 449666807184 = 4501525^2 + 670572^2 .

It is not a de Polignac number, because 20713394132809 - 2¹³ = 20713394124617 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20713394130809) 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, 23352191364 + ... + 23352192250.

Almost surely, 2^{20713394132809} is an apocalyptic number.

20713394132809 is the 4551197-th square number.

20713394132809 is the 2275599-th centered octagonal number.

It is an amenable number.

20713394132809 is a deficient number, since it is larger than the sum of its proper divisors (3441928047518).

20713394132809 is an frugal number, since it uses more digits than its factorization.

20713394132809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3254 (or 1627 counting only the distinct ones).

The product of its (nonzero) digits is 1959552, while the sum is 52.

The spelling of 20713394132809 in words is "twenty trillion, seven hundred thirteen billion, three hundred ninety-four million, one hundred thirty-two thousand, eight hundred nine".