18697213 has 2 divisors, whose sum is σ = 18697214. Its totient is φ = 18697212.

The previous prime is 18697201. The next prime is 18697219. The reversal of 18697213 is 31279681.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 10614564 + 8082649 = 3258^2 + 2843^2 .

It is a cyclic number.

It is not a de Polignac number, because 18697213 - 2²¹ = 16600061 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18697219) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9348606 + 9348607.

It is an arithmetic number, because the mean of its divisors is an integer number (9348607).

Almost surely, 2^18697213 is an apocalyptic number.

It is an amenable number.

18697213 is a deficient number, since it is larger than the sum of its proper divisors (1).

18697213 is an equidigital number, since it uses as much as digits as its factorization.

18697213 is an evil number, because the sum of its binary digits is even.

The product of its digits is 18144, while the sum is 37.

The square root of 18697213 is about 4324.0274050935. The cubic root of 18697213 is about 265.4150988223.

The spelling of 18697213 in words is "eighteen million, six hundred ninety-seven thousand, two hundred thirteen".