85900656640 has 76 divisors (see below), whose sum is σ = 206164328436. Its totient is φ = 34359738368.

The previous prime is 85900656637. The next prime is 85900656689. The reversal of 85900656640 is 4665600958.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 68451303424 + 17449353216 = 261632^2 + 132096^2 .

It is a super-2 number, since 2×85900656640² (a number of 23 digits) contains 22 as substring.

It is a zygodrome in base 4.

It is a congruent number.

It is an unprimeable number.

In principle, a polygon with 85900656640 sides can be constructed with ruler and compass.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1277952 + ... + 1343488.

Almost surely, 2^85900656640 is an apocalyptic number.

85900656640 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 85900656640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (103082164218).

85900656640 is an abundant number, since it is smaller than the sum of its proper divisors (120263671796).

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

85900656640 is an frugal number, since it uses more digits than its factorization.

85900656640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 65578 (or 65544 counting only the distinct ones).

The product of its (nonzero) digits is 1555200, while the sum is 49.

The spelling of 85900656640 in words is "eighty-five billion, nine hundred million, six hundred fifty-six thousand, six hundred forty".