18316973 has 4 divisors (see below), whose sum is σ = 19394460. Its totient is φ = 17239488.

The previous prime is 18316957. The next prime is 18316979. The reversal of 18316973 is 37961381.

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

It can be written as a sum of positive squares in 2 ways, for example, as 17197609 + 1119364 = 4147^2 + 1058^2 .

It is a cyclic number.

It is not a de Polignac number, because 18316973 - 2⁴ = 18316957 is a prime.

It is a super-2 number, since 2×18316973² = 671022999765458, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18316979) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 538718 + ... + 538751.

It is an arithmetic number, because the mean of its divisors is an integer number (4848615).

Almost surely, 2^18316973 is an apocalyptic number.

It is an amenable number.

18316973 is a deficient number, since it is larger than the sum of its proper divisors (1077487).

18316973 is a wasteful number, since it uses less digits than its factorization.

18316973 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1077486.

The product of its digits is 27216, while the sum is 38.

The square root of 18316973 is about 4279.8332911458. The cubic root of 18316973 is about 263.6035380995.

The spelling of 18316973 in words is "eighteen million, three hundred sixteen thousand, nine hundred seventy-three".