18101389 has 4 divisors (see below), whose sum is σ = 18117756. Its totient is φ = 18085024.

The previous prime is 18101383. The next prime is 18101393. The reversal of 18101389 is 98310181.

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

It can be written as a sum of positive squares in 2 ways, for example, as 13564489 + 4536900 = 3683^2 + 2130^2 .

It is a cyclic number.

It is not a de Polignac number, because 18101389 - 2⁹ = 18100877 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

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 18101389.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18101383) 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, 6394 + ... + 8779.

It is an arithmetic number, because the mean of its divisors is an integer number (4529439).

Almost surely, 2^18101389 is an apocalyptic number.

It is an amenable number.

18101389 is a deficient number, since it is larger than the sum of its proper divisors (16367).

18101389 is a wasteful number, since it uses less digits than its factorization.

18101389 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16366.

The product of its (nonzero) digits is 1728, while the sum is 31.

The square root of 18101389 is about 4254.5727165016. The cubic root of 18101389 is about 262.5652820250.

The spelling of 18101389 in words is "eighteen million, one hundred one thousand, three hundred eighty-nine".