18511421313 has 48 divisors (see below), whose sum is σ = 32005664768. Its totient is φ = 9306079200.

The previous prime is 18511421309. The next prime is 18511421351. The reversal of 18511421313 is 31312411581.

It is not a de Polignac number, because 18511421313 - 2² = 18511421309 is a prime.

It is not an unprimeable number, because it can be changed into a prime (18511421393) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 38731 + ... + 196272.

Almost surely, 2^18511421313 is an apocalyptic number.

It is an amenable number.

18511421313 is a deficient number, since it is larger than the sum of its proper divisors (13494243455).

18511421313 is a wasteful number, since it uses less digits than its factorization.

18511421313 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 235066 (or 235055 counting only the distinct ones).

The product of its digits is 2880, while the sum is 30.

Adding to 18511421313 its reverse (31312411581), we get a palindrome (49823832894).

The spelling of 18511421313 in words is "eighteen billion, five hundred eleven million, four hundred twenty-one thousand, three hundred thirteen".