85778209 has 16 divisors (see below), whose sum is σ = 102283776. Its totient is φ = 71020800.

The previous prime is 85778197. The next prime is 85778219. The reversal of 85778209 is 90287758.

It is a cyclic number.

It is not a de Polignac number, because 85778209 - 2⁵ = 85778177 is a prime.

It is a super-2 number, since 2×85778209² = 14715802278495362, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (85778219) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1602 + ... + 13195.

It is an arithmetic number, because the mean of its divisors is an integer number (6392736).

Almost surely, 2^85778209 is an apocalyptic number.

It is an amenable number.

85778209 is a deficient number, since it is larger than the sum of its proper divisors (16505567).

85778209 is a wasteful number, since it uses less digits than its factorization.

85778209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14856.

The product of its (nonzero) digits is 282240, while the sum is 46.

The square root of 85778209 is about 9261.6526063117. The cubic root of 85778209 is about 441.0207174174.

The spelling of 85778209 in words is "eighty-five million, seven hundred seventy-eight thousand, two hundred nine".