91866639241 has 4 divisors (see below), whose sum is σ = 98933303812. Its totient is φ = 84799974672.

The previous prime is 91866639211. The next prime is 91866639247. The reversal of 91866639241 is 14293666819.

It is a happy number.

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 32581694016 + 59284945225 = 180504^2 + 243485^2 .

It is a cyclic number.

It is not a de Polignac number, because 91866639241 - 2²⁵ = 91833084809 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (91866639247) 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, 3533332266 + ... + 3533332291.

It is an arithmetic number, because the mean of its divisors is an integer number (24733325953).

Almost surely, 2^91866639241 is an apocalyptic number.

It is an amenable number.

91866639241 is a deficient number, since it is larger than the sum of its proper divisors (7066664571).

91866639241 is a wasteful number, since it uses less digits than its factorization.

91866639241 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7066664570.

The product of its digits is 3359232, while the sum is 55.

The spelling of 91866639241 in words is "ninety-one billion, eight hundred sixty-six million, six hundred thirty-nine thousand, two hundred forty-one".