81591862 has 16 divisors (see below), whose sum is σ = 134813952. Its totient is φ = 36726120.

The previous prime is 81591827. The next prime is 81591869. The reversal of 81591862 is 26819518.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81591869) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 15738 + ... + 20269.

It is an arithmetic number, because the mean of its divisors is an integer number (8425872).

Almost surely, 2^81591862 is an apocalyptic number.

81591862 is a deficient number, since it is larger than the sum of its proper divisors (53222090).

81591862 is a wasteful number, since it uses less digits than its factorization.

81591862 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36123.

The product of its digits is 34560, while the sum is 40.

The square root of 81591862 is about 9032.8213754065. The cubic root of 81591862 is about 433.7261575314.

The spelling of 81591862 in words is "eighty-one million, five hundred ninety-one thousand, eight hundred sixty-two".