20807999999 has 4 divisors (see below), whose sum is σ = 20809353600. Its totient is φ = 20806646400.

The previous prime is 20807999987. The next prime is 20808000007. The reversal of 20807999999 is 99999970802.

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 20807999999 - 2³² = 16513032703 is a prime.

It is a Duffinian number.

20807999999 is a modest number, since divided by 999999 gives 20807 as remainder.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20807999939) 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, 653474 + ... + 684575.

It is an arithmetic number, because the mean of its divisors is an integer number (5202338400).

Almost surely, 2^20807999999 is an apocalyptic number.

20807999999 is a deficient number, since it is larger than the sum of its proper divisors (1353601).

20807999999 is a wasteful number, since it uses less digits than its factorization.

20807999999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1353600.

The product of its (nonzero) digits is 59521392, while the sum is 71.

The spelling of 20807999999 in words is "twenty billion, eight hundred seven million, nine hundred ninety-nine thousand, nine hundred ninety-nine".