18997730 has 16 divisors (see below), whose sum is σ = 35299584. Its totient is φ = 7353840.

The previous prime is 18997723. The next prime is 18997733. The reversal of 18997730 is 3779981.

It is not an unprimeable number, because it can be changed into a prime (18997733) 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 7 ways as a sum of consecutive naturals, for example, 30332 + ... + 30951.

It is an arithmetic number, because the mean of its divisors is an integer number (2206224).

Almost surely, 2^18997730 is an apocalyptic number.

18997730 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

18997730 is a deficient number, since it is larger than the sum of its proper divisors (16301854).

18997730 is a wasteful number, since it uses less digits than its factorization.

18997730 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 61321.

The product of its (nonzero) digits is 95256, while the sum is 44.

The square root of 18997730 is about 4358.6385489049. The cubic root of 18997730 is about 266.8295376564.

The spelling of 18997730 in words is "eighteen million, nine hundred ninety-seven thousand, seven hundred thirty".