85172939 has 2 divisors, whose sum is σ = 85172940. Its totient is φ = 85172938.

The previous prime is 85172881. The next prime is 85172951. The reversal of 85172939 is 93927158.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 85172939 - 2⁸ = 85172683 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 85172939.

It is not a weakly prime, because it can be changed into another prime (85172639) 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, 42586469 + 42586470.

It is an arithmetic number, because the mean of its divisors is an integer number (42586470).

Almost surely, 2^85172939 is an apocalyptic number.

85172939 is a deficient number, since it is larger than the sum of its proper divisors (1).

85172939 is an equidigital number, since it uses as much as digits as its factorization.

85172939 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 136080, while the sum is 44.

The square root of 85172939 is about 9228.9186257112. The cubic root of 85172939 is about 439.9809547542.

The spelling of 85172939 in words is "eighty-five million, one hundred seventy-two thousand, nine hundred thirty-nine".