82091009 has 16 divisors (see below), whose sum is σ = 110221440. Its totient is φ = 59045760.

The previous prime is 82090993. The next prime is 82091017. The reversal of 82091009 is 90019028.

It is a cyclic number.

It is not a de Polignac number, because 82091009 - 2⁴ = 82090993 is a prime.

It is not an unprimeable number, because it can be changed into a prime (82091089) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 40004 + ... + 42005.

It is an arithmetic number, because the mean of its divisors is an integer number (6888840).

Almost surely, 2^82091009 is an apocalyptic number.

It is an amenable number.

82091009 is a deficient number, since it is larger than the sum of its proper divisors (28130431).

82091009 is a wasteful number, since it uses less digits than its factorization.

82091009 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 82040.

The product of its (nonzero) digits is 1296, while the sum is 29.

The square root of 82091009 is about 9060.4088759835. The cubic root of 82091009 is about 434.6088155404.

The spelling of 82091009 in words is "eighty-two million, ninety-one thousand, nine".