85866781 has 16 divisors (see below), whose sum is σ = 115291008. Its totient is φ = 61761600.

The previous prime is 85866749. The next prime is 85866787. The reversal of 85866781 is 18766858.

It is a cyclic number.

It is not a de Polignac number, because 85866781 - 2⁵ = 85866749 is a prime.

It is a super-2 number, since 2×85866781² = 14746208158603922, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (85866787) 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, 41890 + ... + 43891.

It is an arithmetic number, because the mean of its divisors is an integer number (7205688).

Almost surely, 2^85866781 is an apocalyptic number.

It is an amenable number.

85866781 is a deficient number, since it is larger than the sum of its proper divisors (29424227).

85866781 is a wasteful number, since it uses less digits than its factorization.

85866781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 85812.

The product of its digits is 645120, while the sum is 49.

The square root of 85866781 is about 9266.4330246325. The cubic root of 85866781 is about 441.1724601127.

The spelling of 85866781 in words is "eighty-five million, eight hundred sixty-six thousand, seven hundred eighty-one".