18213656 has 8 divisors (see below), whose sum is σ = 34150620. Its totient is φ = 9106824.

The previous prime is 18213617. The next prime is 18213659. The reversal of 18213656 is 65631281.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (8).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18213659) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1138346 + ... + 1138361.

Almost surely, 2^18213656 is an apocalyptic number.

It is an amenable number.

18213656 is a deficient number, since it is larger than the sum of its proper divisors (15936964).

18213656 is a wasteful number, since it uses less digits than its factorization.

18213656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2276713 (or 2276709 counting only the distinct ones).

The product of its digits is 8640, while the sum is 32.

The square root of 18213656 is about 4267.7460093122. The cubic root of 18213656 is about 263.1069841894.

The spelling of 18213656 in words is "eighteen million, two hundred thirteen thousand, six hundred fifty-six".