18697940 has 12 divisors (see below), whose sum is σ = 39265716. Its totient is φ = 7479168.

The previous prime is 18697907. The next prime is 18697949. The reversal of 18697940 is 4979681.

It can be written as a sum of positive squares in 2 ways, for example, as 8976016 + 9721924 = 2996^2 + 3118^2 .

It is a super-2 number, since 2×18697940² = 699225920487200, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 18697891 and 18697900.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18697949) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 467429 + ... + 467468.

It is an arithmetic number, because the mean of its divisors is an integer number (3272143).

Almost surely, 2^18697940 is an apocalyptic number.

18697940 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18697940 is an abundant number, since it is smaller than the sum of its proper divisors (20567776).

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

18697940 is a wasteful number, since it uses less digits than its factorization.

18697940 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 934906 (or 934904 counting only the distinct ones).

The product of its (nonzero) digits is 108864, while the sum is 44.

The square root of 18697940 is about 4324.1114694235. Note that the first 3 decimals coincide. The cubic root of 18697940 is about 265.4185388051.

The spelling of 18697940 in words is "eighteen million, six hundred ninety-seven thousand, nine hundred forty".