16601571943 has 4 divisors (see below), whose sum is σ = 18110805768. Its totient is φ = 15092338120.

The previous prime is 16601571893. The next prime is 16601571977. The reversal of 16601571943 is 34917510661.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-16601571943 is a prime.

It is a super-2 number, since 2×16601571943² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 16601571943.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16601571643) 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, 754616896 + ... + 754616917.

It is an arithmetic number, because the mean of its divisors is an integer number (4527701442).

Almost surely, 2^16601571943 is an apocalyptic number.

16601571943 is a deficient number, since it is larger than the sum of its proper divisors (1509233825).

16601571943 is a wasteful number, since it uses less digits than its factorization.

16601571943 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1509233824.

The product of its (nonzero) digits is 136080, while the sum is 43.

The spelling of 16601571943 in words is "sixteen billion, six hundred one million, five hundred seventy-one thousand, nine hundred forty-three".