16581942108929 has 4 divisors (see below), whose sum is σ = 16607335589076. Its totient is φ = 16556548628784.

The previous prime is 16581942108913. The next prime is 16581942109037. The reversal of 16581942108929 is 92980124918561.

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

It can be written as a sum of positive squares in 2 ways, for example, as 3939935195329 + 12642006913600 = 1984927^2 + 3555560^2 .

It is a cyclic number.

It is not a de Polignac number, because 16581942108929 - 2⁴ = 16581942108913 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16581942108029) 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, 12696739094 + ... + 12696740399.

It is an arithmetic number, because the mean of its divisors is an integer number (4151833897269).

Almost surely, 2^{16581942108929} is an apocalyptic number.

It is an amenable number.

16581942108929 is a deficient number, since it is larger than the sum of its proper divisors (25393480147).

16581942108929 is an equidigital number, since it uses as much as digits as its factorization.

16581942108929 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25393480146.

The product of its (nonzero) digits is 22394880, while the sum is 65.

The spelling of 16581942108929 in words is "sixteen trillion, five hundred eighty-one billion, nine hundred forty-two million, one hundred eight thousand, nine hundred twenty-nine".