20400386940 has 36 divisors (see below), whose sum is σ = 61881174264. Its totient is φ = 5440103136.

The previous prime is 20400386891. The next prime is 20400386977. The reversal of 20400386940 is 4968300402.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 20400386895 and 20400386904.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 56667562 + ... + 56667921.

Almost surely, 2^20400386940 is an apocalyptic number.

20400386940 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20400386940 is an abundant number, since it is smaller than the sum of its proper divisors (41480787324).

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

20400386940 is a wasteful number, since it uses less digits than its factorization.

20400386940 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 113335498 (or 113335493 counting only the distinct ones).

The product of its (nonzero) digits is 41472, while the sum is 36.

The spelling of 20400386940 in words is "twenty billion, four hundred million, three hundred eighty-six thousand, nine hundred forty".