20396987889 has 16 divisors (see below), whose sum is σ = 29190215232. Its totient is φ = 12622791168.

The previous prime is 20396987843. The next prime is 20396987899. The reversal of 20396987889 is 98878969302.

It is not a de Polignac number, because 20396987889 - 2¹¹ = 20396985841 is a prime.

It is a super-2 number, since 2×20396987889² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (20396987839) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2735599 + ... + 2743044.

It is an arithmetic number, because the mean of its divisors is an integer number (1824388452).

Almost surely, 2^20396987889 is an apocalyptic number.

It is an amenable number.

20396987889 is a deficient number, since it is larger than the sum of its proper divisors (8793227343).

20396987889 is a wasteful number, since it uses less digits than its factorization.

20396987889 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5478736.

The product of its (nonzero) digits is 94058496, while the sum is 69.

The spelling of 20396987889 in words is "twenty billion, three hundred ninety-six million, nine hundred eighty-seven thousand, eight hundred eighty-nine".