18921299 has 2 divisors, whose sum is σ = 18921300. Its totient is φ = 18921298.

The previous prime is 18921293. The next prime is 18921317. The reversal of 18921299 is 99212981.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 18921299 - 2⁸ = 18921043 is a prime.

It is not a weakly prime, because it can be changed into another prime (18921293) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9460649 + 9460650.

It is an arithmetic number, because the mean of its divisors is an integer number (9460650).

Almost surely, 2^18921299 is an apocalyptic number.

18921299 is a deficient number, since it is larger than the sum of its proper divisors (1).

18921299 is an equidigital number, since it uses as much as digits as its factorization.

18921299 is an evil number, because the sum of its binary digits is even.

The product of its digits is 23328, while the sum is 41.

The square root of 18921299 is about 4349.8619518325. The cubic root of 18921299 is about 266.4712236328.

The spelling of 18921299 in words is "eighteen million, nine hundred twenty-one thousand, two hundred ninety-nine".