85766781 has 4 divisors (see below), whose sum is σ = 114355712. Its totient is φ = 57177852.

The previous prime is 85766749. The next prime is 85766789. The reversal of 85766781 is 18766758.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 85766781 - 2⁵ = 85766749 is a prime.

It is a super-2 number, since 2×85766781² = 14711881446203922, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 85766781.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (85766789) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 14294461 + ... + 14294466.

It is an arithmetic number, because the mean of its divisors is an integer number (28588928).

Almost surely, 2^85766781 is an apocalyptic number.

It is an amenable number.

85766781 is a deficient number, since it is larger than the sum of its proper divisors (28588931).

85766781 is a wasteful number, since it uses less digits than its factorization.

85766781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28588930.

The product of its digits is 564480, while the sum is 48.

The square root of 85766781 is about 9261.0356332324. The cubic root of 85766781 is about 441.0011312130.

The spelling of 85766781 in words is "eighty-five million, seven hundred sixty-six thousand, seven hundred eighty-one".