19918499 has 4 divisors (see below), whose sum is σ = 20002080. Its totient is φ = 19834920.

The previous prime is 19918489. The next prime is 19918501. The reversal of 19918499 is 99481991.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 19918499 - 2²⁴ = 3141283 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19918429) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 41432 + ... + 41909.

It is an arithmetic number, because the mean of its divisors is an integer number (5000520).

Almost surely, 2^19918499 is an apocalyptic number.

19918499 is a deficient number, since it is larger than the sum of its proper divisors (83581).

19918499 is an equidigital number, since it uses as much as digits as its factorization.

19918499 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 83580.

The product of its digits is 209952, while the sum is 50.

The square root of 19918499 is about 4463.0145641707. The cubic root of 19918499 is about 271.0725467644.

The spelling of 19918499 in words is "nineteen million, nine hundred eighteen thousand, four hundred ninety-nine".