20920660879 has 4 divisors (see below), whose sum is σ = 21486084184. Its totient is φ = 20355237576.

The previous prime is 20920660877. The next prime is 20920660909. The reversal of 20920660879 is 97806602902.

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

It is a cyclic number.

It is not a de Polignac number, because 20920660879 - 2¹ = 20920660877 is a prime.

It is a super-2 number, since 2×20920660879² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20920660877) 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, 282711597 + ... + 282711670.

It is an arithmetic number, because the mean of its divisors is an integer number (5371521046).

Almost surely, 2^20920660879 is an apocalyptic number.

20920660879 is a deficient number, since it is larger than the sum of its proper divisors (565423305).

20920660879 is an equidigital number, since it uses as much as digits as its factorization.

20920660879 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 565423304.

The product of its (nonzero) digits is 653184, while the sum is 49.

The spelling of 20920660879 in words is "twenty billion, nine hundred twenty million, six hundred sixty thousand, eight hundred seventy-nine".