18121312102213 has 4 divisors (see below), whose sum is σ = 18162590717920. Its totient is φ = 18080033486508.

The previous prime is 18121312102199. The next prime is 18121312102237. The reversal of 18121312102213 is 31220121312181.

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.

It is a cyclic number.

It is not a de Polignac number, because 18121312102213 - 2⁵ = 18121312102181 is a prime.

It is a super-2 number, since 2×18121312102213² (a number of 27 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 (18121312102513) 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, 20639307195 + ... + 20639308072.

It is an arithmetic number, because the mean of its divisors is an integer number (4540647679480).

Almost surely, 2^{18121312102213} is an apocalyptic number.

It is an amenable number.

18121312102213 is a deficient number, since it is larger than the sum of its proper divisors (41278615707).

18121312102213 is an equidigital number, since it uses as much as digits as its factorization.

18121312102213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41278615706.

The product of its (nonzero) digits is 1152, while the sum is 28.

Adding to 18121312102213 its reverse (31220121312181), we get a palindrome (49341433414394).

The spelling of 18121312102213 in words is "eighteen trillion, one hundred twenty-one billion, three hundred twelve million, one hundred two thousand, two hundred thirteen".