20815699773959 has 8 divisors (see below), whose sum is σ = 20855748225312. Its totient is φ = 20775674920960.

The previous prime is 20815699773899. The next prime is 20815699773971. The reversal of 20815699773959 is 95937799651802.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20815699773959 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 (20815699773359) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4133219 + ... + 7662564.

It is an arithmetic number, because the mean of its divisors is an integer number (2606968528164).

Almost surely, 2^{20815699773959} is an apocalyptic number.

20815699773959 is a deficient number, since it is larger than the sum of its proper divisors (40048451353).

20815699773959 is a wasteful number, since it uses less digits than its factorization.

20815699773959 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11799177.

The product of its (nonzero) digits is 2314720800, while the sum is 80.

The spelling of 20815699773959 in words is "twenty trillion, eight hundred fifteen billion, six hundred ninety-nine million, seven hundred seventy-three thousand, nine hundred fifty-nine".