85720013 has 4 divisors (see below), whose sum is σ = 86568828. Its totient is φ = 84871200.

The previous prime is 85720007. The next prime is 85720021. The reversal of 85720013 is 31002758.

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 66945124 + 18774889 = 8182^2 + 4333^2 .

It is a cyclic number.

It is not a de Polignac number, because 85720013 - 2¹⁰ = 85718989 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (85720003) 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, 424256 + ... + 424457.

It is an arithmetic number, because the mean of its divisors is an integer number (21642207).

Almost surely, 2^85720013 is an apocalyptic number.

It is an amenable number.

85720013 is a deficient number, since it is larger than the sum of its proper divisors (848815).

85720013 is a wasteful number, since it uses less digits than its factorization.

85720013 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 848814.

The product of its (nonzero) digits is 1680, while the sum is 26.

The square root of 85720013 is about 9258.5103013390. The cubic root of 85720013 is about 440.9209584055.

The spelling of 85720013 in words is "eighty-five million, seven hundred twenty thousand, thirteen".