18103844261 has 4 divisors (see below), whose sum is σ = 18108319500. Its totient is φ = 18099369024.

The previous prime is 18103844207. The next prime is 18103844273. The reversal of 18103844261 is 16244830181.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 16244830181 = 8761 ⋅1854221.

It can be written as a sum of positive squares in 2 ways, for example, as 3491628100 + 14612216161 = 59090^2 + 120881^2 .

It is a cyclic number.

It is not a de Polignac number, because 18103844261 - 2⁶ = 18103844197 is a prime.

It is a super-2 number, since 2×18103844261² (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 (18103844201) 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, 2231546 + ... + 2239643.

It is an arithmetic number, because the mean of its divisors is an integer number (4527079875).

Almost surely, 2^18103844261 is an apocalyptic number.

It is an amenable number.

18103844261 is a deficient number, since it is larger than the sum of its proper divisors (4475239).

18103844261 is an equidigital number, since it uses as much as digits as its factorization.

18103844261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4475238.

The product of its (nonzero) digits is 36864, while the sum is 38.

The spelling of 18103844261 in words is "eighteen billion, one hundred three million, eight hundred forty-four thousand, two hundred sixty-one".