85721766 has 32 divisors (see below), whose sum is σ = 186375168. Its totient is φ = 26126880.

The previous prime is 85721737. The next prime is 85721777. The reversal of 85721766 is 66712758.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3211 + ... + 13481.

It is an arithmetic number, because the mean of its divisors is an integer number (5824224).

Almost surely, 2^85721766 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 85721766, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (93187584).

85721766 is an abundant number, since it is smaller than the sum of its proper divisors (100653402).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

85721766 is a wasteful number, since it uses less digits than its factorization.

85721766 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10396.

The product of its digits is 141120, while the sum is 42.

The square root of 85721766 is about 9258.6049705126. The cubic root of 85721766 is about 440.9239640403.

The spelling of 85721766 in words is "eighty-five million, seven hundred twenty-one thousand, seven hundred sixty-six".