18816131 has 2 divisors, whose sum is σ = 18816132. Its totient is φ = 18816130.

The previous prime is 18816107. The next prime is 18816173. The reversal of 18816131 is 13161881.

It is a weak prime.

It is an emirp because it is prime and its reverse (13161881) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18816131 is a prime.

It is a super-2 number, since 2×18816131² = 708093571618322, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 18816094 and 18816103.

It is not a weakly prime, because it can be changed into another prime (18816181) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9408065 + 9408066.

It is an arithmetic number, because the mean of its divisors is an integer number (9408066).

Almost surely, 2^18816131 is an apocalyptic number.

18816131 is a deficient number, since it is larger than the sum of its proper divisors (1).

18816131 is an equidigital number, since it uses as much as digits as its factorization.

18816131 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1152, while the sum is 29.

The square root of 18816131 is about 4337.7564477504. The cubic root of 18816131 is about 265.9766077004.

The spelling of 18816131 in words is "eighteen million, eight hundred sixteen thousand, one hundred thirty-one".