82855721 has 4 divisors (see below), whose sum is σ = 89229252. Its totient is φ = 76482192.

The previous prime is 82855693. The next prime is 82855727. The reversal of 82855721 is 12755828.

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 33223696 + 49632025 = 5764^2 + 7045^2 .

It is a cyclic number.

It is not a de Polignac number, because 82855721 - 2¹⁰ = 82854697 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (82855727) 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, 3186746 + ... + 3186771.

It is an arithmetic number, because the mean of its divisors is an integer number (22307313).

Almost surely, 2^82855721 is an apocalyptic number.

It is an amenable number.

82855721 is a deficient number, since it is larger than the sum of its proper divisors (6373531).

82855721 is a wasteful number, since it uses less digits than its factorization.

82855721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6373530.

The product of its digits is 44800, while the sum is 38.

The square root of 82855721 is about 9102.5117962022. The cubic root of 82855721 is about 435.9541674601.

The spelling of 82855721 in words is "eighty-two million, eight hundred fifty-five thousand, seven hundred twenty-one".