20722586509 has 4 divisors (see below), whose sum is σ = 21941562204. Its totient is φ = 19503610816.

The previous prime is 20722586503. The next prime is 20722586551. The reversal of 20722586509 is 90568522702.

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 7948614025 + 12773972484 = 89155^2 + 113022^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20722586509 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 (20722586503) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 609487822 + ... + 609487855.

It is an arithmetic number, because the mean of its divisors is an integer number (5485390551).

Almost surely, 2^20722586509 is an apocalyptic number.

It is an amenable number.

20722586509 is a deficient number, since it is larger than the sum of its proper divisors (1218975695).

20722586509 is a wasteful number, since it uses less digits than its factorization.

20722586509 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1218975694.

The product of its (nonzero) digits is 604800, while the sum is 46.

The spelling of 20722586509 in words is "twenty billion, seven hundred twenty-two million, five hundred eighty-six thousand, five hundred nine".