18691340 has 12 divisors (see below), whose sum is σ = 39251856. Its totient is φ = 7476528.

The previous prime is 18691339. The next prime is 18691391. The reversal of 18691340 is 4319681.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 18691297 and 18691306.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 467264 + ... + 467303.

It is an arithmetic number, because the mean of its divisors is an integer number (3270988).

Almost surely, 2^18691340 is an apocalyptic number.

18691340 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18691340 is an abundant number, since it is smaller than the sum of its proper divisors (20560516).

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

18691340 is a wasteful number, since it uses less digits than its factorization.

18691340 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 934576 (or 934574 counting only the distinct ones).

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

The square root of 18691340 is about 4323.3482395014. The cubic root of 18691340 is about 265.3873059793.

The spelling of 18691340 in words is "eighteen million, six hundred ninety-one thousand, three hundred forty".