20400917823 has 80 divisors (see below), whose sum is σ = 37688112000. Its totient is φ = 10812294720.

The previous prime is 20400917783. The next prime is 20400917839. The reversal of 20400917823 is 32871900402.

It is not a de Polignac number, because 20400917823 - 2⁶ = 20400917759 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20400917843) by changing a digit.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 173728 + ... + 266426.

It is an arithmetic number, because the mean of its divisors is an integer number (471101400).

Almost surely, 2^20400917823 is an apocalyptic number.

20400917823 is a deficient number, since it is larger than the sum of its proper divisors (17287194177).

20400917823 is a wasteful number, since it uses less digits than its factorization.

20400917823 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 92754 (or 92745 counting only the distinct ones).

The product of its (nonzero) digits is 24192, while the sum is 36.

The spelling of 20400917823 in words is "twenty billion, four hundred million, nine hundred seventeen thousand, eight hundred twenty-three".