20910820799 has 4 divisors (see below), whose sum is σ = 22811804520. Its totient is φ = 19009837080.

The previous prime is 20910820787. The next prime is 20910820919. The reversal of 20910820799 is 99702801902.

It is a happy number.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20910820799 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 (20910820759) 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, 950491844 + ... + 950491865.

It is an arithmetic number, because the mean of its divisors is an integer number (5702951130).

Almost surely, 2^20910820799 is an apocalyptic number.

20910820799 is a deficient number, since it is larger than the sum of its proper divisors (1900983721).

20910820799 is a wasteful number, since it uses less digits than its factorization.

20910820799 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1900983720.

The product of its (nonzero) digits is 163296, while the sum is 47.

The spelling of 20910820799 in words is "twenty billion, nine hundred ten million, eight hundred twenty thousand, seven hundred ninety-nine".