85729081 has 9 divisors (see below), whose sum is σ = 88038799. Its totient is φ = 83479144.

The previous prime is 85729067. The next prime is 85729099. The reversal of 85729081 is 18092758.

The square root of 85729081 is 9259.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 83997225 + 1731856 = 9165^2 + 1316^2 .

It is not a de Polignac number, because 85729081 - 2¹³ = 85720889 is a prime.

It is a super-2 number, since 2×85729081² = 14698950658209122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (85729051) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 435075 + ... + 435271.

Almost surely, 2^85729081 is an apocalyptic number.

85729081 is the 9259-th square number.

85729081 is the 4630-th centered octagonal number.

It is an amenable number.

85729081 is a deficient number, since it is larger than the sum of its proper divisors (2309718).

85729081 is an frugal number, since it uses more digits than its factorization.

85729081 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 488 (or 244 counting only the distinct ones).

The product of its (nonzero) digits is 40320, while the sum is 40.

The cubic root of 85729081 is about 440.9365056510.

The spelling of 85729081 in words is "eighty-five million, seven hundred twenty-nine thousand, eighty-one".