18737213 has 12 divisors (see below), whose sum is σ = 21809340. Its totient is φ = 16030080.

The previous prime is 18737177. The next prime is 18737227. The reversal of 18737213 is 31273781.

It can be written as a sum of positive squares in 2 ways, for example, as 7991929 + 10745284 = 2827^2 + 3278^2 .

It is not a de Polignac number, because 18737213 - 2⁶ = 18737149 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 18737213.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18737263) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2498 + ... + 6611.

It is an arithmetic number, because the mean of its divisors is an integer number (1817445).

Almost surely, 2^18737213 is an apocalyptic number.

It is an amenable number.

18737213 is a deficient number, since it is larger than the sum of its proper divisors (3072127).

18737213 is a wasteful number, since it uses less digits than its factorization.

18737213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9148 (or 9137 counting only the distinct ones).

The product of its digits is 7056, while the sum is 32.

The square root of 18737213 is about 4328.6502515218. The cubic root of 18737213 is about 265.6042364946.

The spelling of 18737213 in words is "eighteen million, seven hundred thirty-seven thousand, two hundred thirteen".