18100909991 has 8 divisors (see below), whose sum is σ = 18153506304. Its totient is φ = 18048377880.

The previous prime is 18100909973. The next prime is 18100910011. The reversal of 18100909991 is 19990900181.

It is a happy number.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18100909991 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 (18100909591) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 580406 + ... + 610796.

It is an arithmetic number, because the mean of its divisors is an integer number (2269188288).

Almost surely, 2^18100909991 is an apocalyptic number.

18100909991 is a deficient number, since it is larger than the sum of its proper divisors (52596313).

18100909991 is a wasteful number, since it uses less digits than its factorization.

18100909991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32101.

The product of its (nonzero) digits is 52488, while the sum is 47.

The spelling of 18100909991 in words is "eighteen billion, one hundred million, nine hundred nine thousand, nine hundred ninety-one".