18621730 has 16 divisors (see below), whose sum is σ = 34425720. Its totient is φ = 7247232.

The previous prime is 18621727. The next prime is 18621739. The reversal of 18621730 is 3712681.

It can be written as a sum of positive squares in 4 ways, for example, as 12895281 + 5726449 = 3591^2 + 2393^2 .

It is not an unprimeable number, because it can be changed into a prime (18621739) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 24795 + ... + 25534.

Almost surely, 2^18621730 is an apocalyptic number.

18621730 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

18621730 is a deficient number, since it is larger than the sum of its proper divisors (15803990).

18621730 is a wasteful number, since it uses less digits than its factorization.

18621730 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 50373.

The product of its (nonzero) digits is 2016, while the sum is 28.

The square root of 18621730 is about 4315.2902567498. The cubic root of 18621730 is about 265.0574457164.

The spelling of 18621730 in words is "eighteen million, six hundred twenty-one thousand, seven hundred thirty".