82120905 has 16 divisors (see below), whose sum is σ = 145992960. Its totient is φ = 43797744.

The previous prime is 82120847. The next prime is 82120939. The reversal of 82120905 is 50902128.

It is not a de Polignac number, because 82120905 - 2⁹ = 82120393 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 304017 + ... + 304286.

It is an arithmetic number, because the mean of its divisors is an integer number (9124560).

Almost surely, 2^82120905 is an apocalyptic number.

It is an amenable number.

82120905 is a deficient number, since it is larger than the sum of its proper divisors (63872055).

82120905 is a wasteful number, since it uses less digits than its factorization.

82120905 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 608317 (or 608311 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 27.

The square root of 82120905 is about 9062.0585409718. The cubic root of 82120905 is about 434.6615679199.

The spelling of 82120905 in words is "eighty-two million, one hundred twenty thousand, nine hundred five".