85781000 has 32 divisors (see below), whose sum is σ = 200729880. Its totient is φ = 34312000.

The previous prime is 85780957. The next prime is 85781021. The reversal of 85781000 is 18758.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 46267204 + 39513796 = 6802^2 + 6286^2 .

It is a super-2 number, since 2×85781000² = 14716759922000000, which contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 41891 + ... + 43890.

Almost surely, 2^85781000 is an apocalyptic number.

It is an amenable number.

85781000 is an abundant number, since it is smaller than the sum of its proper divisors (114948880).

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

85781000 is a wasteful number, since it uses less digits than its factorization.

85781000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 85802 (or 85788 counting only the distinct ones).

The product of its (nonzero) digits is 2240, while the sum is 29.

The square root of 85781000 is about 9261.8032801393. The cubic root of 85781000 is about 441.0255005882.

Adding to 85781000 its reverse (18758), we get a palindrome (85799758).

The spelling of 85781000 in words is "eighty-five million, seven hundred eighty-one thousand".