82684021 has 24 divisors (see below), whose sum is σ = 98639640. Its totient is φ = 69092352.

The previous prime is 82684009. The next prime is 82684027. The reversal of 82684021 is 12048628.

It can be written as a sum of positive squares in 4 ways, for example, as 3651921 + 79032100 = 1911^2 + 8890^2 .

It is not a de Polignac number, because 82684021 - 2⁵ = 82683989 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 (82684027) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 603465 + ... + 603601.

It is an arithmetic number, because the mean of its divisors is an integer number (4109985).

Almost surely, 2^82684021 is an apocalyptic number.

It is an amenable number.

82684021 is a deficient number, since it is larger than the sum of its proper divisors (15955619).

82684021 is a wasteful number, since it uses less digits than its factorization.

82684021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 373 (or 366 counting only the distinct ones).

The product of its (nonzero) digits is 6144, while the sum is 31.

The square root of 82684021 is about 9093.0754423352. The cubic root of 82684021 is about 435.6528199496.

The spelling of 82684021 in words is "eighty-two million, six hundred eighty-four thousand, twenty-one".