18609640 has 32 divisors (see below), whose sum is σ = 47854080. Its totient is φ = 6380352.

The previous prime is 18609637. The next prime is 18609673. The reversal of 18609640 is 4690681.

It is a junction number, because it is equal to n+sod(n) for n = 18609596 and 18609605.

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, 32952 + ... + 33511.

It is an arithmetic number, because the mean of its divisors is an integer number (1495440).

Almost surely, 2^18609640 is an apocalyptic number.

18609640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18609640 is an abundant number, since it is smaller than the sum of its proper divisors (29244440).

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

18609640 is a wasteful number, since it uses less digits than its factorization.

18609640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 66481 (or 66477 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 34.

The square root of 18609640 is about 4313.8891965372. The cubic root of 18609640 is about 265.0000711997. Note that the first 4 decimals are identical.

The spelling of 18609640 in words is "eighteen million, six hundred nine thousand, six hundred forty".