82591987 has 4 divisors (see below), whose sum is σ = 83946016. Its totient is φ = 81237960.

The previous prime is 82591979. The next prime is 82591997. The reversal of 82591987 is 78919528.

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 82591987 - 2³ = 82591979 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 82591987.

It is not an unprimeable number, because it can be changed into a prime (82591997) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 676923 + ... + 677044.

It is an arithmetic number, because the mean of its divisors is an integer number (20986504).

Almost surely, 2^82591987 is an apocalyptic number.

82591987 is a deficient number, since it is larger than the sum of its proper divisors (1354029).

82591987 is a wasteful number, since it uses less digits than its factorization.

82591987 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1354028.

The product of its digits is 362880, while the sum is 49.

The square root of 82591987 is about 9088.0133692683. The cubic root of 82591987 is about 435.4911210037.

The spelling of 82591987 in words is "eighty-two million, five hundred ninety-one thousand, nine hundred eighty-seven".