18993371 has 2 divisors, whose sum is σ = 18993372. Its totient is φ = 18993370.

The previous prime is 18993367. The next prime is 18993391. The reversal of 18993371 is 17339981.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 18993371 - 2² = 18993367 is a prime.

It is not a weakly prime, because it can be changed into another prime (18993341) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9496685 + 9496686.

It is an arithmetic number, because the mean of its divisors is an integer number (9496686).

Almost surely, 2^18993371 is an apocalyptic number.

18993371 is a deficient number, since it is larger than the sum of its proper divisors (1).

18993371 is an equidigital number, since it uses as much as digits as its factorization.

18993371 is an evil number, because the sum of its binary digits is even.

The product of its digits is 40824, while the sum is 41.

The square root of 18993371 is about 4358.1384787544. The cubic root of 18993371 is about 266.8091282194.

The spelling of 18993371 in words is "eighteen million, nine hundred ninety-three thousand, three hundred seventy-one".