85281991 has 2 divisors, whose sum is σ = 85281992. Its totient is φ = 85281990.

The previous prime is 85281983. The next prime is 85282007. The reversal of 85281991 is 19918258.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 85281991 - 2³ = 85281983 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (85281941) 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, 42640995 + 42640996.

It is an arithmetic number, because the mean of its divisors is an integer number (42640996).

Almost surely, 2^85281991 is an apocalyptic number.

85281991 is a deficient number, since it is larger than the sum of its proper divisors (1).

85281991 is an equidigital number, since it uses as much as digits as its factorization.

85281991 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 51840, while the sum is 43.

The square root of 85281991 is about 9234.8249035918. The cubic root of 85281991 is about 440.1686526334.

The spelling of 85281991 in words is "eighty-five million, two hundred eighty-one thousand, nine hundred ninety-one".