18129791 has 2 divisors, whose sum is σ = 18129792. Its totient is φ = 18129790.

The previous prime is 18129757. The next prime is 18129847. The reversal of 18129791 is 19792181.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 18129791 - 2²² = 13935487 is a prime.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18129721) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9064895 + 9064896.

It is an arithmetic number, because the mean of its divisors is an integer number (9064896).

Almost surely, 2^18129791 is an apocalyptic number.

18129791 is a deficient number, since it is larger than the sum of its proper divisors (1).

18129791 is an equidigital number, since it uses as much as digits as its factorization.

18129791 is an evil number, because the sum of its binary digits is even.

The product of its digits is 9072, while the sum is 38.

The square root of 18129791 is about 4257.9092287178. The cubic root of 18129791 is about 262.7025363576.

The spelling of 18129791 in words is "eighteen million, one hundred twenty-nine thousand, seven hundred ninety-one".