18438001 has 2 divisors, whose sum is σ = 18438002. Its totient is φ = 18438000.

The previous prime is 18437981. The next prime is 18438023. The reversal of 18438001 is 10083481.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15800625 + 2637376 = 3975^2 + 1624^2 .

It is a cyclic number.

It is not a de Polignac number, because 18438001 - 2⁷ = 18437873 is a prime.

It is not a weakly prime, because it can be changed into another prime (18436001) 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 as a sum of consecutive naturals, namely, 9219000 + 9219001.

It is an arithmetic number, because the mean of its divisors is an integer number (9219001).

Almost surely, 2^18438001 is an apocalyptic number.

It is an amenable number.

18438001 is a deficient number, since it is larger than the sum of its proper divisors (1).

18438001 is an equidigital number, since it uses as much as digits as its factorization.

18438001 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 768, while the sum is 25.

The square root of 18438001 is about 4293.9493476286. The cubic root of 18438001 is about 264.1828441410.

The spelling of 18438001 in words is "eighteen million, four hundred thirty-eight thousand, one".