20985788995 has 4 divisors (see below), whose sum is σ = 25182946800. Its totient is φ = 16788631192.

The previous prime is 20985788939. The next prime is 20985789023. The reversal of 20985788995 is 59988758902.

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 20985788995 - 2¹⁵ = 20985756227 is a prime.

It is a super-2 number, since 2×20985788995² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2098578895 + ... + 2098578904.

It is an arithmetic number, because the mean of its divisors is an integer number (6295736700).

Almost surely, 2^20985788995 is an apocalyptic number.

20985788995 is a deficient number, since it is larger than the sum of its proper divisors (4197157805).

20985788995 is an equidigital number, since it uses as much as digits as its factorization.

20985788995 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4197157804.

The product of its (nonzero) digits is 130636800, while the sum is 70.

The spelling of 20985788995 in words is "twenty billion, nine hundred eighty-five million, seven hundred eighty-eight thousand, nine hundred ninety-five".