18768661 has 4 divisors (see below), whose sum is σ = 18857824. Its totient is φ = 18679500.

The previous prime is 18768653. The next prime is 18768679. The reversal of 18768661 is 16686781.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 18768661 - 2³ = 18768653 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18768641) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 44265 + ... + 44686.

It is an arithmetic number, because the mean of its divisors is an integer number (4714456).

Almost surely, 2^18768661 is an apocalyptic number.

It is an amenable number.

18768661 is a deficient number, since it is larger than the sum of its proper divisors (89163).

18768661 is an equidigital number, since it uses as much as digits as its factorization.

18768661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 89162.

The product of its digits is 96768, while the sum is 43.

The square root of 18768661 is about 4332.2812697238. The cubic root of 18768661 is about 265.7527476133.

The spelling of 18768661 in words is "eighteen million, seven hundred sixty-eight thousand, six hundred sixty-one".