18400671 has 6 divisors (see below), whose sum is σ = 26578760. Its totient is φ = 12267108.

The previous prime is 18400651. The next prime is 18400673. The reversal of 18400671 is 17600481.

It is a happy number.

It is not a de Polignac number, because 18400671 - 2²¹ = 16303519 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18400673) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1022251 + ... + 1022268.

Almost surely, 2^18400671 is an apocalyptic number.

18400671 is a deficient number, since it is larger than the sum of its proper divisors (8178089).

18400671 is a wasteful number, since it uses less digits than its factorization.

18400671 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2044525 (or 2044522 counting only the distinct ones).

The product of its (nonzero) digits is 1344, while the sum is 27.

The square root of 18400671 is about 4289.6003310332. The cubic root of 18400671 is about 264.0044334655.

It can be divided in two parts, 18 and 400671, that added together give a square (400689 = 633²).

The spelling of 18400671 in words is "eighteen million, four hundred thousand, six hundred seventy-one".