20689686240 has 48 divisors (see below), whose sum is σ = 65172513168. Its totient is φ = 5517249536.

The previous prime is 20689686221. The next prime is 20689686293. The reversal of 20689686240 is 4268698602.

It is a tau number, because it is divible by the number of its divisors (48).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 21551277 + ... + 21552236.

It is an arithmetic number, because the mean of its divisors is an integer number (1357760691).

Almost surely, 2^20689686240 is an apocalyptic number.

20689686240 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20689686240 is an abundant number, since it is smaller than the sum of its proper divisors (44482826928).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20689686240 is a wasteful number, since it uses less digits than its factorization.

20689686240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43103531 (or 43103523 counting only the distinct ones).

The product of its (nonzero) digits is 1990656, while the sum is 51.

The spelling of 20689686240 in words is "twenty billion, six hundred eighty-nine million, six hundred eighty-six thousand, two hundred forty".