18940099 has 4 divisors (see below), whose sum is σ = 18949680. Its totient is φ = 18930520.

The previous prime is 18940079. The next prime is 18940127. The reversal of 18940099 is 99004981.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 99004981 = 3739 ⋅26479.

It is a cyclic number.

It is not a de Polignac number, because 18940099 - 2⁵ = 18940067 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18940079) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 607 + ... + 6184.

It is an arithmetic number, because the mean of its divisors is an integer number (4737420).

Almost surely, 2^18940099 is an apocalyptic number.

18940099 is a deficient number, since it is larger than the sum of its proper divisors (9581).

18940099 is an equidigital number, since it uses as much as digits as its factorization.

18940099 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9580.

The product of its (nonzero) digits is 23328, while the sum is 40.

The square root of 18940099 is about 4352.0224034350. The cubic root of 18940099 is about 266.5594487372.

It can be divided in two parts, 1 and 8940099, that added together give a square (8940100 = 2990²).

The spelling of 18940099 in words is "eighteen million, nine hundred forty thousand, ninety-nine".