20504755979 has 4 divisors (see below), whose sum is σ = 21211816560. Its totient is φ = 19797695400.

The previous prime is 20504755963. The next prime is 20504755981. The reversal of 20504755979 is 97955740502.

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 20504755979 - 2⁴ = 20504755963 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20504755979.

It is not an unprimeable number, because it can be changed into a prime (20504755079) 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, 353530247 + ... + 353530304.

It is an arithmetic number, because the mean of its divisors is an integer number (5302954140).

Almost surely, 2^20504755979 is an apocalyptic number.

20504755979 is a gapful number since it is divisible by the number (29) formed by its first and last digit.

20504755979 is a deficient number, since it is larger than the sum of its proper divisors (707060581).

20504755979 is an equidigital number, since it uses as much as digits as its factorization.

20504755979 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 707060580.

The product of its (nonzero) digits is 3969000, while the sum is 53.

The spelling of 20504755979 in words is "twenty billion, five hundred four million, seven hundred fifty-five thousand, nine hundred seventy-nine".