20500779731 has 4 divisors (see below), whose sum is σ = 21207703200. Its totient is φ = 19793856264.

The previous prime is 20500779709. The next prime is 20500779751. The reversal of 20500779731 is 13797700502.

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 20500779731 - 2¹⁴ = 20500763347 is a prime.

It is a super-2 number, since 2×20500779731² (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 (20500779701) 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, 353461691 + ... + 353461748.

It is an arithmetic number, because the mean of its divisors is an integer number (5301925800).

Almost surely, 2^20500779731 is an apocalyptic number.

20500779731 is a deficient number, since it is larger than the sum of its proper divisors (706923469).

20500779731 is an equidigital number, since it uses as much as digits as its factorization.

20500779731 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 706923468.

The product of its (nonzero) digits is 92610, while the sum is 41.

The spelling of 20500779731 in words is "twenty billion, five hundred million, seven hundred seventy-nine thousand, seven hundred thirty-one".