18872993 has 2 divisors, whose sum is σ = 18872994. Its totient is φ = 18872992.

The previous prime is 18872969. The next prime is 18873053. The reversal of 18872993 is 39927881.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13778944 + 5094049 = 3712^2 + 2257^2 .

It is a cyclic number.

It is not a de Polignac number, because 18872993 - 2¹⁴ = 18856609 is a prime.

It is not a weakly prime, because it can be changed into another prime (18872093) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9436496 + 9436497.

It is an arithmetic number, because the mean of its divisors is an integer number (9436497).

Almost surely, 2^18872993 is an apocalyptic number.

It is an amenable number.

18872993 is a deficient number, since it is larger than the sum of its proper divisors (1).

18872993 is an equidigital number, since it uses as much as digits as its factorization.

18872993 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 217728, while the sum is 47.

The square root of 18872993 is about 4344.3058133607. The cubic root of 18872993 is about 266.2442637276.

The spelling of 18872993 in words is "eighteen million, eight hundred seventy-two thousand, nine hundred ninety-three".