16581193855 has 8 divisors (see below), whose sum is σ = 19898360064. Its totient is φ = 13264336800.

The previous prime is 16581193829. The next prime is 16581193859. The reversal of 16581193855 is 55839118561.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a de Polignac number, because none of the positive numbers 2^k-16581193855 is a prime.

It is a super-2 number, since 2×16581193855² (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 (16581193859) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 64290 + ... + 193120.

It is an arithmetic number, because the mean of its divisors is an integer number (2487295008).

Almost surely, 2^16581193855 is an apocalyptic number.

16581193855 is a deficient number, since it is larger than the sum of its proper divisors (3317166209).

16581193855 is a wasteful number, since it uses less digits than its factorization.

16581193855 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 154577.

The product of its digits is 1296000, while the sum is 52.

The spelling of 16581193855 in words is "sixteen billion, five hundred eighty-one million, one hundred ninety-three thousand, eight hundred fifty-five".