18681632 has 12 divisors (see below), whose sum is σ = 36779526. Its totient is φ = 9340800.

The previous prime is 18681613. The next prime is 18681643. The reversal of 18681632 is 23618681.

It can be written as a sum of positive squares in only one way, i.e., 17673616 + 1008016 = 4204^2 + 1004^2 .

It is a Smith number, since the sum of its digits (35) coincides with the sum of the digits of its prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 18681592 and 18681601.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 291869 + ... + 291932.

Almost surely, 2^18681632 is an apocalyptic number.

It is an amenable number.

18681632 is a deficient number, since it is larger than the sum of its proper divisors (18097894).

18681632 is an equidigital number, since it uses as much as digits as its factorization.

18681632 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 583811 (or 583803 counting only the distinct ones).

The product of its digits is 13824, while the sum is 35.

The square root of 18681632 is about 4322.2253527552. The cubic root of 18681632 is about 265.3413519682.

It can be divided in two parts, 186 and 81632, that added together give a palindrome (81818).

The spelling of 18681632 in words is "eighteen million, six hundred eighty-one thousand, six hundred thirty-two".