18385400438 has 8 divisors (see below), whose sum is σ = 27730466400. Its totient is φ = 9141911640.

The previous prime is 18385400419. The next prime is 18385400447. The reversal of 18385400438 is 83400458381.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×18385400438² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 25393838 + ... + 25394561.

It is an arithmetic number, because the mean of its divisors is an integer number (3466308300).

Almost surely, 2^18385400438 is an apocalyptic number.

18385400438 is a deficient number, since it is larger than the sum of its proper divisors (9345065962).

18385400438 is a wasteful number, since it uses less digits than its factorization.

18385400438 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 50788582.

The product of its (nonzero) digits is 368640, while the sum is 44.

The spelling of 18385400438 in words is "eighteen billion, three hundred eighty-five million, four hundred thousand, four hundred thirty-eight".