20807137213 has 4 divisors (see below), whose sum is σ = 20823797500. Its totient is φ = 20790476928.

The previous prime is 20807137187. The next prime is 20807137231. The reversal of 20807137213 is 31273170802.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 4738532569 + 16068604644 = 68837^2 + 126762^2 .

It is a cyclic number.

It is not a de Polignac number, because 20807137213 - 2¹⁷ = 20807006141 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20807137313) 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, 8328270 + ... + 8330767.

It is an arithmetic number, because the mean of its divisors is an integer number (5205949375).

Almost surely, 2^20807137213 is an apocalyptic number.

It is an amenable number.

20807137213 is a deficient number, since it is larger than the sum of its proper divisors (16660287).

20807137213 is a wasteful number, since it uses less digits than its factorization.

20807137213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16660286.

The product of its (nonzero) digits is 14112, while the sum is 34.

The spelling of 20807137213 in words is "twenty billion, eight hundred seven million, one hundred thirty-seven thousand, two hundred thirteen".