85178389 has 2 divisors, whose sum is σ = 85178390. Its totient is φ = 85178388.

The previous prime is 85178363. The next prime is 85178411. The reversal of 85178389 is 98387158.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 69639025 + 15539364 = 8345^2 + 3942^2 .

It is a cyclic number.

It is not a de Polignac number, because 85178389 - 2⁹ = 85177877 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (85178339) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 42589194 + 42589195.

It is an arithmetic number, because the mean of its divisors is an integer number (42589195).

Almost surely, 2^85178389 is an apocalyptic number.

It is an amenable number.

85178389 is a deficient number, since it is larger than the sum of its proper divisors (1).

85178389 is an equidigital number, since it uses as much as digits as its factorization.

85178389 is an evil number, because the sum of its binary digits is even.

The product of its digits is 483840, while the sum is 49.

The square root of 85178389 is about 9229.2138885173. The cubic root of 85178389 is about 439.9903389752.

The spelling of 85178389 in words is "eighty-five million, one hundred seventy-eight thousand, three hundred eighty-nine".