82828721 has 2 divisors, whose sum is σ = 82828722. Its totient is φ = 82828720.

The previous prime is 82828717. The next prime is 82828741. The reversal of 82828721 is 12782828.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 50566321 + 32262400 = 7111^2 + 5680^2 .

It is a cyclic number.

It is not a de Polignac number, because 82828721 - 2² = 82828717 is a prime.

It is not a weakly prime, because it can be changed into another prime (82828741) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 41414360 + 41414361.

It is an arithmetic number, because the mean of its divisors is an integer number (41414361).

Almost surely, 2^82828721 is an apocalyptic number.

It is an amenable number.

82828721 is a deficient number, since it is larger than the sum of its proper divisors (1).

82828721 is an equidigital number, since it uses as much as digits as its factorization.

82828721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 28672, while the sum is 38.

The square root of 82828721 is about 9101.0285682444. The cubic root of 82828721 is about 435.9068078605.

The spelling of 82828721 in words is "eighty-two million, eight hundred twenty-eight thousand, seven hundred twenty-one".