81250170 has 64 divisors (see below), whose sum is σ = 205165440. Its totient is φ = 20563200.

The previous prime is 81250153. The next prime is 81250193. The reversal of 81250170 is 7105218.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 81250170.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 52305 + ... + 53835.

It is an arithmetic number, because the mean of its divisors is an integer number (3205710).

Almost surely, 2^81250170 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81250170, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (102582720).

81250170 is an abundant number, since it is smaller than the sum of its proper divisors (123915270).

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

81250170 is a wasteful number, since it uses less digits than its factorization.

81250170 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1631.

The product of its (nonzero) digits is 560, while the sum is 24.

The square root of 81250170 is about 9013.8876185584. The cubic root of 81250170 is about 433.1198547434.

Adding to 81250170 its reverse (7105218), we get a palindrome (88355388).

The spelling of 81250170 in words is "eighty-one million, two hundred fifty thousand, one hundred seventy".