18400473 has 32 divisors (see below), whose sum is σ = 33555200. Its totient is φ = 9704448.

The previous prime is 18400451. The next prime is 18400489. The reversal of 18400473 is 37400481.

It is not a de Polignac number, because 18400473 - 2⁵ = 18400441 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (18400423) 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 31 ways as a sum of consecutive naturals, for example, 1288 + ... + 6201.

It is an arithmetic number, because the mean of its divisors is an integer number (1048600).

Almost surely, 2^18400473 is an apocalyptic number.

18400473 is a gapful number since it is divisible by the number (13) formed by its first and last digit.

It is an amenable number.

18400473 is a deficient number, since it is larger than the sum of its proper divisors (15154727).

18400473 is a wasteful number, since it uses less digits than its factorization.

18400473 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7518 (or 7512 counting only the distinct ones).

The product of its (nonzero) digits is 2688, while the sum is 27.

The square root of 18400473 is about 4289.5772518979. The cubic root of 18400473 is about 264.0034865242.

The spelling of 18400473 in words is "eighteen million, four hundred thousand, four hundred seventy-three".