87271991999 has 4 divisors (see below), whose sum is σ = 87278760240. Its totient is φ = 87265223760.

The previous prime is 87271991977. The next prime is 87271992007. The reversal of 87271991999 is 99919917278.

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 87271991999 - 2¹⁶ = 87271926463 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 (87271993999) 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, 3364742 + ... + 3390579.

It is an arithmetic number, because the mean of its divisors is an integer number (21819690060).

Almost surely, 2^87271991999 is an apocalyptic number.

87271991999 is a deficient number, since it is larger than the sum of its proper divisors (6768241).

87271991999 is a wasteful number, since it uses less digits than its factorization.

87271991999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6768240.

The product of its digits is 46294416, while the sum is 71.

The spelling of 87271991999 in words is "eighty-seven billion, two hundred seventy-one million, nine hundred ninety-one thousand, nine hundred ninety-nine".