84447991 has 2 divisors, whose sum is σ = 84447992. Its totient is φ = 84447990.

The previous prime is 84447983. The next prime is 84447997. The reversal of 84447991 is 19974448.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 84447991 - 2³ = 84447983 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (84447997) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 42223995 + 42223996.

It is an arithmetic number, because the mean of its divisors is an integer number (42223996).

Almost surely, 2^84447991 is an apocalyptic number.

84447991 is a deficient number, since it is larger than the sum of its proper divisors (1).

84447991 is an equidigital number, since it uses as much as digits as its factorization.

84447991 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 290304, while the sum is 46.

The square root of 84447991 is about 9189.5588033376. The cubic root of 84447991 is about 438.7290995258.

The spelling of 84447991 in words is "eighty-four million, four hundred forty-seven thousand, nine hundred ninety-one".