18621320 has 32 divisors (see below), whose sum is σ = 42189120. Its totient is φ = 7396800.

The previous prime is 18621319. The next prime is 18621331. The reversal of 18621320 is 2312681.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4499 + ... + 7581.

It is an arithmetic number, because the mean of its divisors is an integer number (1318410).

Almost surely, 2^18621320 is an apocalyptic number.

18621320 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18621320 is an abundant number, since it is smaller than the sum of its proper divisors (23567800).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

18621320 is a wasteful number, since it uses less digits than its factorization.

18621320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3245 (or 3241 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 23.

The square root of 18621320 is about 4315.2427509933. The cubic root of 18621320 is about 265.0555004200.

The spelling of 18621320 in words is "eighteen million, six hundred twenty-one thousand, three hundred twenty".