18936971 has 4 divisors (see below), whose sum is σ = 19590000. Its totient is φ = 18283944.

The previous prime is 18936923. The next prime is 18936979. The reversal of 18936971 is 17963981.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18936971 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18936979) 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, 326471 + ... + 326528.

It is an arithmetic number, because the mean of its divisors is an integer number (4897500).

Almost surely, 2^18936971 is an apocalyptic number.

18936971 is a deficient number, since it is larger than the sum of its proper divisors (653029).

18936971 is an equidigital number, since it uses as much as digits as its factorization.

18936971 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 653028.

The product of its digits is 81648, while the sum is 44.

The square root of 18936971 is about 4351.6630154459. The cubic root of 18936971 is about 266.5447736316.

The spelling of 18936971 in words is "eighteen million, nine hundred thirty-six thousand, nine hundred seventy-one".