16591139887 has 4 divisors (see below), whose sum is σ = 18961302736. Its totient is φ = 14220977040.

The previous prime is 16591139879. The next prime is 16591139921. The reversal of 16591139887 is 78893119561.

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 16591139887 - 2³ = 16591139879 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16591139837) 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, 1185081414 + ... + 1185081427.

It is an arithmetic number, because the mean of its divisors is an integer number (4740325684).

Almost surely, 2^16591139887 is an apocalyptic number.

16591139887 is a deficient number, since it is larger than the sum of its proper divisors (2370162849).

16591139887 is an equidigital number, since it uses as much as digits as its factorization.

16591139887 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2370162848.

The product of its digits is 3265920, while the sum is 58.

The spelling of 16591139887 in words is "sixteen billion, five hundred ninety-one million, one hundred thirty-nine thousand, eight hundred eighty-seven".