85021729 has 4 divisors (see below), whose sum is σ = 91561876. Its totient is φ = 78481584.

The previous prime is 85021697. The next prime is 85021753. The reversal of 85021729 is 92712058.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 44355600 + 40666129 = 6660^2 + 6377^2 .

It is a cyclic number.

It is not a de Polignac number, because 85021729 - 2⁵ = 85021697 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 85021694 and 85021703.

It is not an unprimeable number, because it can be changed into a prime (85021759) 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, 3270054 + ... + 3270079.

It is an arithmetic number, because the mean of its divisors is an integer number (22890469).

Almost surely, 2^85021729 is an apocalyptic number.

It is an amenable number.

85021729 is a deficient number, since it is larger than the sum of its proper divisors (6540147).

85021729 is a wasteful number, since it uses less digits than its factorization.

85021729 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6540146.

The product of its (nonzero) digits is 10080, while the sum is 34.

The square root of 85021729 is about 9220.7228024705. The cubic root of 85021729 is about 439.7204301853.

The spelling of 85021729 in words is "eighty-five million, twenty-one thousand, seven hundred twenty-nine".