18187795949 has 4 divisors (see below), whose sum is σ = 18246277920. Its totient is φ = 18129313980.

The previous prime is 18187795937. The next prime is 18187795973. The reversal of 18187795949 is 94959778181.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 94959778181 = 31 ⋅3063218651.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18187795949 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18187792949) 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, 29240519 + ... + 29241140.

It is an arithmetic number, because the mean of its divisors is an integer number (4561569480).

Almost surely, 2^18187795949 is an apocalyptic number.

It is an amenable number.

18187795949 is a deficient number, since it is larger than the sum of its proper divisors (58481971).

18187795949 is an equidigital number, since it uses as much as digits as its factorization.

18187795949 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 58481970.

The product of its digits is 45722880, while the sum is 68.

The spelling of 18187795949 in words is "eighteen billion, one hundred eighty-seven million, seven hundred ninety-five thousand, nine hundred forty-nine".