18400965 has 16 divisors (see below), whose sum is σ = 32118336. Its totient is φ = 8921600.

The previous prime is 18400961. The next prime is 18400969. The reversal of 18400965 is 56900481.

It is an interprime number because it is at equal distance from previous prime (18400961) and next prime (18400969).

It is not a de Polignac number, because 18400965 - 2² = 18400961 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18400961) 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 15 ways as a sum of consecutive naturals, for example, 55596 + ... + 55925.

It is an arithmetic number, because the mean of its divisors is an integer number (2007396).

Almost surely, 2^18400965 is an apocalyptic number.

18400965 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

18400965 is a deficient number, since it is larger than the sum of its proper divisors (13717371).

18400965 is a wasteful number, since it uses less digits than its factorization.

18400965 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 111540.

The product of its (nonzero) digits is 8640, while the sum is 33.

The square root of 18400965 is about 4289.6345998232. The cubic root of 18400965 is about 264.0058395173.

The spelling of 18400965 in words is "eighteen million, four hundred thousand, nine hundred sixty-five".