85434441991 has 2 divisors, whose sum is σ = 85434441992. Its totient is φ = 85434441990.

The previous prime is 85434441979. The next prime is 85434442081. The reversal of 85434441991 is 19914443458.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 85434441991 - 2¹⁵ = 85434409223 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (85434541991) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 42717220995 + 42717220996.

It is an arithmetic number, because the mean of its divisors is an integer number (42717220996).

Almost surely, 2^85434441991 is an apocalyptic number.

85434441991 is a deficient number, since it is larger than the sum of its proper divisors (1).

85434441991 is an equidigital number, since it uses as much as digits as its factorization.

85434441991 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2488320, while the sum is 52.

The spelling of 85434441991 in words is "eighty-five billion, four hundred thirty-four million, four hundred forty-one thousand, nine hundred ninety-one".