81627685 has 16 divisors (see below), whose sum is σ = 100951920. Its totient is φ = 63331840.

The previous prime is 81627683. The next prime is 81627691. The reversal of 81627685 is 58672618.

It can be written as a sum of positive squares in 8 ways, for example, as 6441444 + 75186241 = 2538^2 + 8671^2 .

It is not a de Polignac number, because 81627685 - 2¹ = 81627683 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81627683) 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 15 ways as a sum of consecutive naturals, for example, 21855 + ... + 25315.

It is an arithmetic number, because the mean of its divisors is an integer number (6309495).

Almost surely, 2^81627685 is an apocalyptic number.

It is an amenable number.

81627685 is a deficient number, since it is larger than the sum of its proper divisors (19324235).

81627685 is a wasteful number, since it uses less digits than its factorization.

81627685 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3608.

The product of its digits is 161280, while the sum is 43.

The square root of 81627685 is about 9034.8040930615. The cubic root of 81627685 is about 433.7896242318.

The spelling of 81627685 in words is "eighty-one million, six hundred twenty-seven thousand, six hundred eighty-five".