18870331 has 2 divisors, whose sum is σ = 18870332. Its totient is φ = 18870330.

The previous prime is 18870317. The next prime is 18870343. The reversal of 18870331 is 13307881.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 18870331 - 2¹⁵ = 18837563 is a prime.

It is a super-2 number, since 2×18870331² = 712178784099122, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 18870293 and 18870302.

It is not a weakly prime, because it can be changed into another prime (18870361) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9435165 + 9435166.

It is an arithmetic number, because the mean of its divisors is an integer number (9435166).

Almost surely, 2^18870331 is an apocalyptic number.

18870331 is a deficient number, since it is larger than the sum of its proper divisors (1).

18870331 is an equidigital number, since it uses as much as digits as its factorization.

18870331 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4032, while the sum is 31.

The square root of 18870331 is about 4343.9994244935. Note that the first 3 decimals coincide. The cubic root of 18870331 is about 266.2317453890.

The spelling of 18870331 in words is "eighteen million, eight hundred seventy thousand, three hundred thirty-one".