84811891 has 2 divisors, whose sum is σ = 84811892. Its totient is φ = 84811890.

The previous prime is 84811873. The next prime is 84811913. The reversal of 84811891 is 19811848.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 84811891 - 2¹³ = 84803699 is a prime.

It is not a weakly prime, because it can be changed into another prime (84811841) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 42405945 + 42405946.

It is an arithmetic number, because the mean of its divisors is an integer number (42405946).

Almost surely, 2^84811891 is an apocalyptic number.

84811891 is a deficient number, since it is larger than the sum of its proper divisors (1).

84811891 is an equidigital number, since it uses as much as digits as its factorization.

84811891 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 18432, while the sum is 40.

The square root of 84811891 is about 9209.3371639874. The cubic root of 84811891 is about 439.3583812908.

The spelling of 84811891 in words is "eighty-four million, eight hundred eleven thousand, eight hundred ninety-one".