81250111 has 4 divisors (see below), whose sum is σ = 82229112. Its totient is φ = 80271112.

The previous prime is 81250073. The next prime is 81250133. The reversal of 81250111 is 11105218.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 11105218 = 2 ⋅5552609.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81250111 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81250511) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 489376 + ... + 489541.

It is an arithmetic number, because the mean of its divisors is an integer number (20557278).

Almost surely, 2^81250111 is an apocalyptic number.

81250111 is a deficient number, since it is larger than the sum of its proper divisors (979001).

81250111 is an equidigital number, since it uses as much as digits as its factorization.

81250111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 979000.

The product of its (nonzero) digits is 80, while the sum is 19.

The square root of 81250111 is about 9013.8843458300. The cubic root of 81250111 is about 433.1197499063.

Adding to 81250111 its reverse (11105218), we get a palindrome (92355329).

The spelling of 81250111 in words is "eighty-one million, two hundred fifty thousand, one hundred eleven".