18257213 has 8 divisors (see below), whose sum is σ = 19695648. Its totient is φ = 16823664.

The previous prime is 18257207. The next prime is 18257249. The reversal of 18257213 is 31275281.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 18257213 - 2¹² = 18253117 is a prime.

It is a super-4 number, since 4×18257213⁴ (a number of 30 digits) contains 4444 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 (18257203) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11570 + ... + 13052.

It is an arithmetic number, because the mean of its divisors is an integer number (2461956).

Almost surely, 2^18257213 is an apocalyptic number.

18257213 is a gapful number since it is divisible by the number (13) formed by its first and last digit.

It is an amenable number.

18257213 is a deficient number, since it is larger than the sum of its proper divisors (1438435).

18257213 is a wasteful number, since it uses less digits than its factorization.

18257213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2443.

The product of its digits is 3360, while the sum is 29.

The square root of 18257213 is about 4272.8460070543. The cubic root of 18257213 is about 263.3165527237.

It can be divided in two parts, 182 and 57213, that multiplied together give a triangular number (10412766 = T₄₅₆₃).

The spelling of 18257213 in words is "eighteen million, two hundred fifty-seven thousand, two hundred thirteen".