18958213 has 4 divisors (see below), whose sum is σ = 20073420. Its totient is φ = 17843008.

The previous prime is 18958193. The next prime is 18958217. The reversal of 18958213 is 31285981.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 31285981 = 139 ⋅225079.

It can be written as a sum of positive squares in 2 ways, for example, as 15108769 + 3849444 = 3887^2 + 1962^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18958213 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18958217) 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, 557578 + ... + 557611.

It is an arithmetic number, because the mean of its divisors is an integer number (5018355).

Almost surely, 2^18958213 is an apocalyptic number.

It is an amenable number.

18958213 is a deficient number, since it is larger than the sum of its proper divisors (1115207).

18958213 is a wasteful number, since it uses less digits than its factorization.

18958213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1115206.

The product of its digits is 17280, while the sum is 37.

The square root of 18958213 is about 4354.1030075091. The cubic root of 18958213 is about 266.6443993560.

The spelling of 18958213 in words is "eighteen million, nine hundred fifty-eight thousand, two hundred thirteen".