18997765 has 8 divisors (see below), whose sum is σ = 22826520. Its totient is φ = 15178752.

The previous prime is 18997757. The next prime is 18997799. The reversal of 18997765 is 56779981.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 7935489 + 11062276 = 2817^2 + 3326^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 18997765 - 2³ = 18997757 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2941 + ... + 6829.

It is an arithmetic number, because the mean of its divisors is an integer number (2853315).

Almost surely, 2^18997765 is an apocalyptic number.

It is an amenable number.

18997765 is a deficient number, since it is larger than the sum of its proper divisors (3828755).

18997765 is an equidigital number, since it uses as much as digits as its factorization.

18997765 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4871.

The product of its digits is 952560, while the sum is 52.

The square root of 18997765 is about 4358.6425639183. The cubic root of 18997765 is about 266.8297015186.

The spelling of 18997765 in words is "eighteen million, nine hundred ninety-seven thousand, seven hundred sixty-five".