16505543431 has 4 divisors (see below), whose sum is σ = 17775200632. Its totient is φ = 15235886232.

The previous prime is 16505543413. The next prime is 16505543449. The reversal of 16505543431 is 13434550561.

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

It is an interprime number because it is at equal distance from previous prime (16505543413) and next prime (16505543449).

It is a cyclic number.

It is not a de Polignac number, because 16505543431 - 2⁷ = 16505543303 is a prime.

It is a super-2 number, since 2×16505543431² (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 (16505543531) 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, 634828581 + ... + 634828606.

It is an arithmetic number, because the mean of its divisors is an integer number (4443800158).

Almost surely, 2^16505543431 is an apocalyptic number.

16505543431 is a deficient number, since it is larger than the sum of its proper divisors (1269657201).

16505543431 is a wasteful number, since it uses less digits than its factorization.

16505543431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1269657200.

The product of its (nonzero) digits is 108000, while the sum is 37.

The spelling of 16505543431 in words is "sixteen billion, five hundred five million, five hundred forty-three thousand, four hundred thirty-one".