20800656739 has 4 divisors (see below), whose sum is σ = 20886966760. Its totient is φ = 20714346720.

The previous prime is 20800656689. The next prime is 20800656757. The reversal of 20800656739 is 93765600802.

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 20800656739 - 2¹⁵ = 20800623971 is a prime.

It is a super-2 number, since 2×20800656739² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20800656439) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 43154649 + ... + 43155130.

It is an arithmetic number, because the mean of its divisors is an integer number (5221741690).

Almost surely, 2^20800656739 is an apocalyptic number.

20800656739 is a deficient number, since it is larger than the sum of its proper divisors (86310021).

20800656739 is an equidigital number, since it uses as much as digits as its factorization.

20800656739 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 86310020.

The product of its (nonzero) digits is 544320, while the sum is 46.

The spelling of 20800656739 in words is "twenty billion, eight hundred million, six hundred fifty-six thousand, seven hundred thirty-nine".