18121302113 has 4 divisors (see below), whose sum is σ = 18137526420. Its totient is φ = 18105077808.

The previous prime is 18121302107. The next prime is 18121302119. The reversal of 18121302113 is 31120312181.

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

It is an interprime number because it is at equal distance from previous prime (18121302107) and next prime (18121302119).

It can be written as a sum of positive squares in 2 ways, for example, as 6618310609 + 11502991504 = 81353^2 + 107252^2 .

It is a cyclic number.

It is not a de Polignac number, because 18121302113 - 2⁶ = 18121302049 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (18121302119) 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, 8110478 + ... + 8112711.

It is an arithmetic number, because the mean of its divisors is an integer number (4534381605).

Almost surely, 2^18121302113 is an apocalyptic number.

It is an amenable number.

18121302113 is a deficient number, since it is larger than the sum of its proper divisors (16224307).

18121302113 is a wasteful number, since it uses less digits than its factorization.

18121302113 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16224306.

The product of its (nonzero) digits is 288, while the sum is 23.

Adding to 18121302113 its reverse (31120312181), we get a palindrome (49241614294).

The spelling of 18121302113 in words is "eighteen billion, one hundred twenty-one million, three hundred two thousand, one hundred thirteen".