18739213 has 2 divisors, whose sum is σ = 18739214. Its totient is φ = 18739212.

The previous prime is 18739211. The next prime is 18739223. The reversal of 18739213 is 31293781.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18003049 + 736164 = 4243^2 + 858^2 .

It is a cyclic number.

It is not a de Polignac number, because 18739213 - 2¹ = 18739211 is a prime.

Together with 18739211, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18739211) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9369606 + 9369607.

It is an arithmetic number, because the mean of its divisors is an integer number (9369607).

Almost surely, 2^18739213 is an apocalyptic number.

It is an amenable number.

18739213 is a deficient number, since it is larger than the sum of its proper divisors (1).

18739213 is an equidigital number, since it uses as much as digits as its factorization.

18739213 is an evil number, because the sum of its binary digits is even.

The product of its digits is 9072, while the sum is 34.

The square root of 18739213 is about 4328.8812642529. The cubic root of 18739213 is about 265.6136863094.

The spelling of 18739213 in words is "eighteen million, seven hundred thirty-nine thousand, two hundred thirteen".