18000009391 has 16 divisors (see below), whose sum is σ = 22917787200. Its totient is φ = 13750668288.

The previous prime is 18000009371. The next prime is 18000009457. The reversal of 18000009391 is 19390000081.

It is not a de Polignac number, because 18000009391 - 2⁷ = 18000009263 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18000009331) 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, 3407746 + ... + 3413023.

It is an arithmetic number, because the mean of its divisors is an integer number (1432361700).

Almost surely, 2^18000009391 is an apocalyptic number.

18000009391 is a deficient number, since it is larger than the sum of its proper divisors (4917777809).

18000009391 is a wasteful number, since it uses less digits than its factorization.

18000009391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6820818.

The product of its (nonzero) digits is 1944, while the sum is 31.

The spelling of 18000009391 in words is "eighteen billion, nine thousand, three hundred ninety-one".