85236561 has 12 divisors (see below), whose sum is σ = 125443188. Its totient is φ = 55751904.

The previous prime is 85236559. The next prime is 85236587. The reversal of 85236561 is 16563258.

It can be written as a sum of positive squares in 2 ways, for example, as 70560000 + 14676561 = 8400^2 + 3831^2 .

It is not a de Polignac number, because 85236561 - 2¹ = 85236559 is a prime.

It is a super-2 number, since 2×85236561² = 14530542662213442, which contains 22 as substring.

It is an alternating number because its digits alternate between even and odd.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (85236161) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 88870 + ... + 89823.

It is an arithmetic number, because the mean of its divisors is an integer number (10453599).

Almost surely, 2^85236561 is an apocalyptic number.

It is an amenable number.

85236561 is a deficient number, since it is larger than the sum of its proper divisors (40206627).

85236561 is a wasteful number, since it uses less digits than its factorization.

85236561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 178752 (or 178749 counting only the distinct ones).

The product of its digits is 43200, while the sum is 36.

The square root of 85236561 is about 9232.3648649737. The cubic root of 85236561 is about 440.0904789827.

The spelling of 85236561 in words is "eighty-five million, two hundred thirty-six thousand, five hundred sixty-one".