18400038 has 16 divisors (see below), whose sum is σ = 37214640. Its totient is φ = 6064256.

The previous prime is 18400013. The next prime is 18400049. The reversal of 18400038 is 83000481.

It is a super-2 number, since 2×18400038² = 677122796802888, which contains 22 as substring.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 18399990 and 18400017.

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, 16695 + ... + 17762.

It is an arithmetic number, because the mean of its divisors is an integer number (2325915).

Almost surely, 2^18400038 is an apocalyptic number.

18400038 is an abundant number, since it is smaller than the sum of its proper divisors (18814602).

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

18400038 is a wasteful number, since it uses less digits than its factorization.

18400038 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34551.

The product of its (nonzero) digits is 768, while the sum is 24.

The square root of 18400038 is about 4289.5265473010. The cubic root of 18400038 is about 264.0014060990.

The spelling of 18400038 in words is "eighteen million, four hundred thousand, thirty-eight".