81285795 has 64 divisors (see below), whose sum is σ = 154275840. Its totient is φ = 40512384.

The previous prime is 81285793. The next prime is 81285803. The reversal of 81285795 is 59758218.

It is a happy number.

It is not a de Polignac number, because 81285795 - 2¹ = 81285793 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 81285795.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81285793) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 145657 + ... + 146213.

It is an arithmetic number, because the mean of its divisors is an integer number (2410560).

Almost surely, 2^81285795 is an apocalyptic number.

81285795 is a deficient number, since it is larger than the sum of its proper divisors (72990045).

81285795 is a wasteful number, since it uses less digits than its factorization.

81285795 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 641 (or 635 counting only the distinct ones).

The product of its digits is 201600, while the sum is 45.

The square root of 81285795 is about 9015.8635193752. The cubic root of 81285795 is about 433.1831474940.

The spelling of 81285795 in words is "eighty-one million, two hundred eighty-five thousand, seven hundred ninety-five".