84639557 has 2 divisors, whose sum is σ = 84639558. Its totient is φ = 84639556.

The previous prime is 84639551. The next prime is 84639589. The reversal of 84639557 is 75593648.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 84621601 + 17956 = 9199^2 + 134^2 .

It is a cyclic number.

It is not a de Polignac number, because 84639557 - 2¹⁸ = 84377413 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (84639551) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 42319778 + 42319779.

It is an arithmetic number, because the mean of its divisors is an integer number (42319779).

Almost surely, 2^84639557 is an apocalyptic number.

It is an amenable number.

84639557 is a deficient number, since it is larger than the sum of its proper divisors (1).

84639557 is an equidigital number, since it uses as much as digits as its factorization.

84639557 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 907200, while the sum is 47.

The square root of 84639557 is about 9199.9759238815. The cubic root of 84639557 is about 439.0605939229.

The spelling of 84639557 in words is "eighty-four million, six hundred thirty-nine thousand, five hundred fifty-seven".