81111190 has 64 divisors (see below), whose sum is σ = 162570240. Its totient is φ = 29013120.

The previous prime is 81111187. The next prime is 81111193. The reversal of 81111190 is 9111118.

81111190 = 61² + 62² + ... + 624².

It is an interprime number because it is at equal distance from previous prime (81111187) and next prime (81111193).

It is a super-2 number, since 2×81111190² = 13158050286432200, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81111193) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 276684 + ... + 276976.

It is an arithmetic number, because the mean of its divisors is an integer number (2540160).

Almost surely, 2^81111190 is an apocalyptic number.

81111190 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

81111190 is a wasteful number, since it uses less digits than its factorization.

81111190 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 397.

The product of its (nonzero) digits is 72, while the sum is 22.

The square root of 81111190 is about 9006.1751037830. The cubic root of 81111190 is about 432.8727604844.

Subtracting from 81111190 its product of nonzero digits (72), we obtain a palindrome (81111118).

The spelling of 81111190 in words is "eighty-one million, one hundred eleven thousand, one hundred ninety".