18135195409 has 4 divisors (see below), whose sum is σ = 18135482404. Its totient is φ = 18134908416.

The previous prime is 18135195401. The next prime is 18135195427. The reversal of 18135195409 is 90459153181.

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

It can be written as a sum of positive squares in 2 ways, for example, as 13023374400 + 5111821009 = 114120^2 + 71497^2 .

It is a cyclic number.

It is not a de Polignac number, because 18135195409 - 2³ = 18135195401 is a prime.

It is a super-2 number, since 2×18135195409² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18135195401) 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, 2592 + ... + 190465.

It is an arithmetic number, because the mean of its divisors is an integer number (4533870601).

Almost surely, 2^18135195409 is an apocalyptic number.

It is an amenable number.

18135195409 is a deficient number, since it is larger than the sum of its proper divisors (286995).

18135195409 is an equidigital number, since it uses as much as digits as its factorization.

18135195409 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 286994.

The product of its (nonzero) digits is 194400, while the sum is 46.

The spelling of 18135195409 in words is "eighteen billion, one hundred thirty-five million, one hundred ninety-five thousand, four hundred nine".