16381381231 has 4 divisors (see below), whose sum is σ = 16445122272. Its totient is φ = 16317640192.

The previous prime is 16381381229. The next prime is 16381381253. The reversal of 16381381231 is 13218318361.

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

It is a cyclic number.

It is not a de Polignac number, because 16381381231 - 2¹ = 16381381229 is a prime.

It is a super-2 number, since 2×16381381231² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16381391231) 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, 31870135 + ... + 31870648.

It is an arithmetic number, because the mean of its divisors is an integer number (4111280568).

Almost surely, 2^16381381231 is an apocalyptic number.

16381381231 is a deficient number, since it is larger than the sum of its proper divisors (63741041).

16381381231 is an equidigital number, since it uses as much as digits as its factorization.

16381381231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 63741040.

The product of its digits is 20736, while the sum is 37.

Adding to 16381381231 its reverse (13218318361), we get a palindrome (29599699592).

The spelling of 16381381231 in words is "sixteen billion, three hundred eighty-one million, three hundred eighty-one thousand, two hundred thirty-one".