18993413 has 2 divisors, whose sum is σ = 18993414. Its totient is φ = 18993412.

The previous prime is 18993397. The next prime is 18993419. The reversal of 18993413 is 31439981.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14122564 + 4870849 = 3758^2 + 2207^2 .

It is a cyclic number.

It is not a de Polignac number, because 18993413 - 2⁴ = 18993397 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18993419) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9496706 + 9496707.

It is an arithmetic number, because the mean of its divisors is an integer number (9496707).

Almost surely, 2^18993413 is an apocalyptic number.

It is an amenable number.

18993413 is a deficient number, since it is larger than the sum of its proper divisors (1).

18993413 is an equidigital number, since it uses as much as digits as its factorization.

18993413 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 23328, while the sum is 38.

The square root of 18993413 is about 4358.1432973228. The cubic root of 18993413 is about 266.8093248840.

The spelling of 18993413 in words is "eighteen million, nine hundred ninety-three thousand, four hundred thirteen".