82722721 has 2 divisors, whose sum is σ = 82722722. Its totient is φ = 82722720.

The previous prime is 82722709. The next prime is 82722727. The reversal of 82722721 is 12722728.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 69906321 + 12816400 = 8361^2 + 3580^2 .

It is a cyclic number.

It is not a de Polignac number, because 82722721 - 2¹³ = 82714529 is a prime.

It is not a weakly prime, because it can be changed into another prime (82722727) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 41361360 + 41361361.

It is an arithmetic number, because the mean of its divisors is an integer number (41361361).

Almost surely, 2^82722721 is an apocalyptic number.

It is an amenable number.

82722721 is a deficient number, since it is larger than the sum of its proper divisors (1).

82722721 is an equidigital number, since it uses as much as digits as its factorization.

82722721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6272, while the sum is 31.

The square root of 82722721 is about 9095.2031862955. The cubic root of 82722721 is about 435.7207779993.

The spelling of 82722721 in words is "eighty-two million, seven hundred twenty-two thousand, seven hundred twenty-one".