18291020113 has 4 divisors (see below), whose sum is σ = 18342836388. Its totient is φ = 18239203840.

The previous prime is 18291020107. The next prime is 18291020119. The reversal of 18291020113 is 31102019281.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 31102019281 = 67 ⋅464209243.

It is an interprime number because it is at equal distance from previous prime (18291020107) and next prime (18291020119).

It can be written as a sum of positive squares in 2 ways, for example, as 9637741584 + 8653278529 = 98172^2 + 93023^2 .

It is a cyclic number.

It is not a de Polignac number, because 18291020113 - 2²¹ = 18288922961 is a prime.

It is a super-2 number, since 2×18291020113² (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 (18291020119) 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, 25907608 + ... + 25908313.

It is an arithmetic number, because the mean of its divisors is an integer number (4585709097).

Almost surely, 2^18291020113 is an apocalyptic number.

It is an amenable number.

18291020113 is a deficient number, since it is larger than the sum of its proper divisors (51816275).

18291020113 is an equidigital number, since it uses as much as digits as its factorization.

18291020113 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 51816274.

The product of its (nonzero) digits is 864, while the sum is 28.

Adding to 18291020113 its reverse (31102019281), we get a palindrome (49393039394).

The spelling of 18291020113 in words is "eighteen billion, two hundred ninety-one million, twenty thousand, one hundred thirteen".