18990746399 has 4 divisors (see below), whose sum is σ = 19017159840. Its totient is φ = 18964332960.

The previous prime is 18990746387. The next prime is 18990746407. The reversal of 18990746399 is 99364709981.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 99364709981 = 79 ⋅1257781139.

It is a cyclic number.

It is not a de Polignac number, because 18990746399 - 2⁸ = 18990746143 is a prime.

It is a super-2 number, since 2×18990746399² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18990796399) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13205642 + ... + 13207079.

It is an arithmetic number, because the mean of its divisors is an integer number (4754289960).

Almost surely, 2^18990746399 is an apocalyptic number.

18990746399 is a deficient number, since it is larger than the sum of its proper divisors (26413441).

18990746399 is an equidigital number, since it uses as much as digits as its factorization.

18990746399 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26413440.

The product of its (nonzero) digits is 26453952, while the sum is 65.

The spelling of 18990746399 in words is "eighteen billion, nine hundred ninety million, seven hundred forty-six thousand, three hundred ninety-nine".