18628720 has 40 divisors (see below), whose sum is σ = 47251440. Its totient is φ = 6773760.

The previous prime is 18628717. The next prime is 18628733. The reversal of 18628720 is 2782681.

It is a tau number, because it is divible by the number of its divisors (40).

It is a Smith number, since the sum of its digits (34) coincides with the sum of the digits of its prime factors.

It is a congruent number.

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, 9705 + ... + 11464.

It is an arithmetic number, because the mean of its divisors is an integer number (1181286).

Almost surely, 2^18628720 is an apocalyptic number.

18628720 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18628720 is an abundant number, since it is smaller than the sum of its proper divisors (28622720).

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

18628720 is a wasteful number, since it uses less digits than its factorization.

18628720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21193 (or 21187 counting only the distinct ones).

The product of its (nonzero) digits is 10752, while the sum is 34.

The square root of 18628720 is about 4316.1000915178. The cubic root of 18628720 is about 265.0906062547.

The spelling of 18628720 in words is "eighteen million, six hundred twenty-eight thousand, seven hundred twenty".