18711131 has 2 divisors, whose sum is σ = 18711132. Its totient is φ = 18711130.

The previous prime is 18711109. The next prime is 18711137. The reversal of 18711131 is 13111781.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18711131 is a prime.

It is a super-2 number, since 2×18711131² = 700212846598322, which contains 22 as substring.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 18711097 and 18711106.

It is not a weakly prime, because it can be changed into another prime (18711137) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9355565 + 9355566.

It is an arithmetic number, because the mean of its divisors is an integer number (9355566).

Almost surely, 2^18711131 is an apocalyptic number.

18711131 is a deficient number, since it is larger than the sum of its proper divisors (1).

18711131 is an equidigital number, since it uses as much as digits as its factorization.

18711131 is an evil number, because the sum of its binary digits is even.

The product of its digits is 168, while the sum is 23.

The square root of 18711131 is about 4325.6364849580. The cubic root of 18711131 is about 265.4809398494.

The spelling of 18711131 in words is "eighteen million, seven hundred eleven thousand, one hundred thirty-one".