18631940 has 12 divisors (see below), whose sum is σ = 39127116. Its totient is φ = 7452768.

The previous prime is 18631939. The next prime is 18631957. The reversal of 18631940 is 4913681.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 4674244 + 13957696 = 2162^2 + 3736^2 .

It is a junction number, because it is equal to n+sod(n) for n = 18631897 and 18631906.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 465779 + ... + 465818.

It is an arithmetic number, because the mean of its divisors is an integer number (3260593).

Almost surely, 2^18631940 is an apocalyptic number.

18631940 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18631940 is an abundant number, since it is smaller than the sum of its proper divisors (20495176).

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

18631940 is a wasteful number, since it uses less digits than its factorization.

18631940 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 931606 (or 931604 counting only the distinct ones).

The product of its (nonzero) digits is 5184, while the sum is 32.

The square root of 18631940 is about 4316.4730973331. The cubic root of 18631940 is about 265.1058791340.

The spelling of 18631940 in words is "eighteen million, six hundred thirty-one thousand, nine hundred forty".