82668821 has 16 divisors (see below), whose sum is σ = 87671040. Its totient is φ = 77837760.

The previous prime is 82668799. The next prime is 82668827. The reversal of 82668821 is 12886628.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-82668821 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 (82668827) 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, 304916 + ... + 305186.

It is an arithmetic number, because the mean of its divisors is an integer number (5479440).

Almost surely, 2^82668821 is an apocalyptic number.

It is an amenable number.

82668821 is a deficient number, since it is larger than the sum of its proper divisors (5002219).

82668821 is a wasteful number, since it uses less digits than its factorization.

82668821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 524.

The product of its digits is 73728, while the sum is 41.

The square root of 82668821 is about 9092.2396030901. The cubic root of 82668821 is about 435.6261226159.

The spelling of 82668821 in words is "eighty-two million, six hundred sixty-eight thousand, eight hundred twenty-one".