85309381 has 2 divisors, whose sum is σ = 85309382. Its totient is φ = 85309380.

The previous prime is 85309379. The next prime is 85309391. The reversal of 85309381 is 18390358.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 48525156 + 36784225 = 6966^2 + 6065^2 .

It is a cyclic number.

It is not a de Polignac number, because 85309381 - 2¹ = 85309379 is a prime.

It is a super-2 number, since 2×85309381² = 14555380973206322, which contains 22 as substring.

Together with 85309379, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 85309381.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (85309331) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 42654690 + 42654691.

It is an arithmetic number, because the mean of its divisors is an integer number (42654691).

Almost surely, 2^85309381 is an apocalyptic number.

It is an amenable number.

85309381 is a deficient number, since it is larger than the sum of its proper divisors (1).

85309381 is an equidigital number, since it uses as much as digits as its factorization.

85309381 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 25920, while the sum is 37.

The square root of 85309381 is about 9236.3077579734. The cubic root of 85309381 is about 440.2157705489.

The spelling of 85309381 in words is "eighty-five million, three hundred nine thousand, three hundred eighty-one".