18249999991 has 8 divisors (see below), whose sum is σ = 19200397104. Its totient is φ = 17323663680.

The previous prime is 18249999983. The next prime is 18249999997. The reversal of 18249999991 is 19999994281.

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 18249999991 - 2³ = 18249999983 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 18249999991.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18249999997) 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, 6013645 + ... + 6016678.

It is an arithmetic number, because the mean of its divisors is an integer number (2400049638).

Almost surely, 2^18249999991 is an apocalyptic number.

18249999991 is a deficient number, since it is larger than the sum of its proper divisors (950397113).

18249999991 is a wasteful number, since it uses less digits than its factorization.

18249999991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12030401.

The product of its digits is 34012224, while the sum is 70.

The spelling of 18249999991 in words is "eighteen billion, two hundred forty-nine million, nine hundred ninety-nine thousand, nine hundred ninety-one".