18397531407 has 16 divisors (see below), whose sum is σ = 24950059520. Its totient is φ = 12055804992.

The previous prime is 18397531379. The next prime is 18397531409. The reversal of 18397531407 is 70413579381.

It is not a de Polignac number, because 18397531407 - 2¹⁰ = 18397530383 is a prime.

It is the 135638-th Hogben number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18397531409) by changing a digit.

It is a nontrivial repunit in base 135637.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5782 + ... + 191907.

It is an arithmetic number, because the mean of its divisors is an integer number (1559378720).

Almost surely, 2^18397531407 is an apocalyptic number.

18397531407 is a deficient number, since it is larger than the sum of its proper divisors (6552528113).

18397531407 is a wasteful number, since it uses less digits than its factorization.

18397531407 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 198222.

The product of its (nonzero) digits is 635040, while the sum is 48.

The spelling of 18397531407 in words is "eighteen billion, three hundred ninety-seven million, five hundred thirty-one thousand, four hundred seven".