81171628 has 12 divisors (see below), whose sum is σ = 142462152. Its totient is φ = 40468160.

The previous prime is 81171611. The next prime is 81171689. The reversal of 81171628 is 82617118.

It is a junction number, because it is equal to n+sod(n) for n = 81171593 and 81171602.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 27853 + ... + 30628.

It is an arithmetic number, because the mean of its divisors is an integer number (11871846).

Almost surely, 2^81171628 is an apocalyptic number.

It is an amenable number.

81171628 is a deficient number, since it is larger than the sum of its proper divisors (61290524).

81171628 is a wasteful number, since it uses less digits than its factorization.

81171628 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 58832 (or 58830 counting only the distinct ones).

The product of its digits is 5376, while the sum is 34.

The square root of 81171628 is about 9009.5298434491. The cubic root of 81171628 is about 432.9802486070.

The spelling of 81171628 in words is "eighty-one million, one hundred seventy-one thousand, six hundred twenty-eight".