18997641 has 24 divisors (see below), whose sum is σ = 29698760. Its totient is φ = 11632896.

The previous prime is 18997633. The next prime is 18997661. The reversal of 18997641 is 14679981.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 4822416 + 14175225 = 2196^2 + 3765^2 .

It is not a de Polignac number, because 18997641 - 2³ = 18997633 is a prime.

It is not an unprimeable number, because it can be changed into a prime (18997631) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 46245 + ... + 46653.

Almost surely, 2^18997641 is an apocalyptic number.

It is an amenable number.

18997641 is a deficient number, since it is larger than the sum of its proper divisors (10701119).

18997641 is a wasteful number, since it uses less digits than its factorization.

18997641 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 825 (or 822 counting only the distinct ones).

The product of its digits is 108864, while the sum is 45.

The square root of 18997641 is about 4358.6283392829. The cubic root of 18997641 is about 266.8291209774.

The spelling of 18997641 in words is "eighteen million, nine hundred ninety-seven thousand, six hundred forty-one".