18198431 has 2 divisors, whose sum is σ = 18198432. Its totient is φ = 18198430.

The previous prime is 18198407. The next prime is 18198469. The reversal of 18198431 is 13489181.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 18198431 - 2²² = 14004127 is a prime.

It is a super-2 number, since 2×18198431² = 662365781723522, 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 = 18198391 and 18198400.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18191431) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9099215 + 9099216.

It is an arithmetic number, because the mean of its divisors is an integer number (9099216).

Almost surely, 2^18198431 is an apocalyptic number.

18198431 is a deficient number, since it is larger than the sum of its proper divisors (1).

18198431 is an equidigital number, since it uses as much as digits as its factorization.

18198431 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6912, while the sum is 35.

The square root of 18198431 is about 4265.9619079406. The cubic root of 18198431 is about 263.0336523897.

The spelling of 18198431 in words is "eighteen million, one hundred ninety-eight thousand, four hundred thirty-one".