18775686991 has 16 divisors (see below), whose sum is σ = 19912413888. Its totient is φ = 17667936000.

The previous prime is 18775686989. The next prime is 18775687003. The reversal of 18775686991 is 19968657781.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 18775686991 - 2¹ = 18775686989 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 (18775686901) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 338971 + ... + 390451.

It is an arithmetic number, because the mean of its divisors is an integer number (1244525868).

Almost surely, 2^18775686991 is an apocalyptic number.

18775686991 is a deficient number, since it is larger than the sum of its proper divisors (1136726897).

18775686991 is a wasteful number, since it uses less digits than its factorization.

18775686991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 51762.

The product of its digits is 45722880, while the sum is 67.

The spelling of 18775686991 in words is "eighteen billion, seven hundred seventy-five million, six hundred eighty-six thousand, nine hundred ninety-one".