84839406721 has 2 divisors, whose sum is σ = 84839406722. Its totient is φ = 84839406720.

The previous prime is 84839406709. The next prime is 84839406731. The reversal of 84839406721 is 12760493848.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 54493766721 + 30345640000 = 233439^2 + 174200^2 .

It is a cyclic number.

It is not a de Polignac number, because 84839406721 - 2³⁵ = 50479668353 is a prime.

It is not a weakly prime, because it can be changed into another prime (84839406731) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 42419703360 + 42419703361.

It is an arithmetic number, because the mean of its divisors is an integer number (42419703361).

Almost surely, 2^84839406721 is an apocalyptic number.

It is an amenable number.

84839406721 is a deficient number, since it is larger than the sum of its proper divisors (1).

84839406721 is an equidigital number, since it uses as much as digits as its factorization.

84839406721 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2322432, while the sum is 52.

The spelling of 84839406721 in words is "eighty-four billion, eight hundred thirty-nine million, four hundred six thousand, seven hundred twenty-one".