18521761066 has 4 divisors (see below), whose sum is σ = 27782641602. Its totient is φ = 9260880532.

The previous prime is 18521761033. The next prime is 18521761079. The reversal of 18521761066 is 66016712581.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 15902471025 + 2619290041 = 126105^2 + 51179^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4630440265 + ... + 4630440268.

Almost surely, 2^18521761066 is an apocalyptic number.

18521761066 is a deficient number, since it is larger than the sum of its proper divisors (9260880536).

18521761066 is an equidigital number, since it uses as much as digits as its factorization.

18521761066 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9260880535.

The product of its (nonzero) digits is 120960, while the sum is 43.

The spelling of 18521761066 in words is "eighteen billion, five hundred twenty-one million, seven hundred sixty-one thousand, sixty-six".