18129817 has 4 divisors (see below), whose sum is σ = 18138640. Its totient is φ = 18120996.

The previous prime is 18129791. The next prime is 18129847. The reversal of 18129817 is 71892181.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 18129817 - 2⁷ = 18129689 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18129847) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 478 + ... + 6040.

It is an arithmetic number, because the mean of its divisors is an integer number (4534660).

Almost surely, 2^18129817 is an apocalyptic number.

It is an amenable number.

18129817 is a deficient number, since it is larger than the sum of its proper divisors (8823).

18129817 is an equidigital number, since it uses as much as digits as its factorization.

18129817 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8822.

The product of its digits is 8064, while the sum is 37.

The square root of 18129817 is about 4257.9122818583. The cubic root of 18129817 is about 262.7026619384.

The spelling of 18129817 in words is "eighteen million, one hundred twenty-nine thousand, eight hundred seventeen".