82105991 has 8 divisors (see below), whose sum is σ = 89771664. Its totient is φ = 74473920.

The previous prime is 82105987. The next prime is 82106009. The reversal of 82105991 is 19950128.

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

It is a cyclic number.

It is not a de Polignac number, because 82105991 - 2² = 82105987 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 (82105901) 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, 3140 + ... + 13193.

It is an arithmetic number, because the mean of its divisors is an integer number (11221458).

Almost surely, 2^82105991 is an apocalyptic number.

82105991 is a deficient number, since it is larger than the sum of its proper divisors (7665673).

82105991 is a wasteful number, since it uses less digits than its factorization.

82105991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16801.

The product of its (nonzero) digits is 6480, while the sum is 35.

The square root of 82105991 is about 9061.2356221434. The cubic root of 82105991 is about 434.6352533248.

The spelling of 82105991 in words is "eighty-two million, one hundred five thousand, nine hundred ninety-one".