18438999393 has 16 divisors (see below), whose sum is σ = 24631494336. Its totient is φ = 12269611200.

The previous prime is 18438999373. The next prime is 18438999427. The reversal of 18438999393 is 39399983481.

It is a happy number.

It is not a de Polignac number, because 18438999393 - 2¹³ = 18438991201 is a prime.

It is not an unprimeable number, because it can be changed into a prime (18438999373) 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, 4705471 + ... + 4709387.

It is an arithmetic number, because the mean of its divisors is an integer number (1539468396).

Almost surely, 2^18438999393 is an apocalyptic number.

It is an amenable number.

18438999393 is a deficient number, since it is larger than the sum of its proper divisors (6192494943).

18438999393 is a wasteful number, since it uses less digits than its factorization.

18438999393 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6464.

The product of its digits is 45349632, while the sum is 66.

The spelling of 18438999393 in words is "eighteen billion, four hundred thirty-eight million, nine hundred ninety-nine thousand, three hundred ninety-three".