18402199857 has 6 divisors (see below), whose sum is σ = 26580955362. Its totient is φ = 12268133232.

The previous prime is 18402199813. The next prime is 18402199877. The reversal of 18402199857 is 75899120481.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 15704851761 + 2697348096 = 125319^2 + 51936^2 .

It is not a de Polignac number, because 18402199857 - 2⁶ = 18402199793 is a prime.

It is not an unprimeable number, because it can be changed into a prime (18402199807) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1022344428 + ... + 1022344445.

It is an arithmetic number, because the mean of its divisors is an integer number (4430159227).

Almost surely, 2^18402199857 is an apocalyptic number.

It is an amenable number.

18402199857 is a deficient number, since it is larger than the sum of its proper divisors (8178755505).

18402199857 is a wasteful number, since it uses less digits than its factorization.

18402199857 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2044688879 (or 2044688876 counting only the distinct ones).

The product of its (nonzero) digits is 1451520, while the sum is 54.

The spelling of 18402199857 in words is "eighteen billion, four hundred two million, one hundred ninety-nine thousand, eight hundred fifty-seven".