18400071 has 8 divisors (see below), whose sum is σ = 24599680. Its totient is φ = 12233592.

The previous prime is 18400061. The next prime is 18400073. The reversal of 18400071 is 17000481.

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

It is not a de Polignac number, because 18400071 - 2⁷ = 18399943 is a prime.

It is a super-2 number, since 2×18400071² = 677125225610082, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18400073) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6955 + ... + 9228.

It is an arithmetic number, because the mean of its divisors is an integer number (3074960).

Almost surely, 2^18400071 is an apocalyptic number.

18400071 is a deficient number, since it is larger than the sum of its proper divisors (6199609).

18400071 is a wasteful number, since it uses less digits than its factorization.

18400071 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16565.

The product of its (nonzero) digits is 224, while the sum is 21.

The square root of 18400071 is about 4289.5303938776. The cubic root of 18400071 is about 264.0015639255.

The spelling of 18400071 in words is "eighteen million, four hundred thousand, seventy-one".