81501673 has 16 divisors (see below), whose sum is σ = 94315392. Its totient is φ = 69696000.

The previous prime is 81501671. The next prime is 81501691. The reversal of 81501673 is 37610518.

It is not a de Polignac number, because 81501673 - 2¹ = 81501671 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81501671) 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 15 ways as a sum of consecutive naturals, for example, 12793 + ... + 18073.

It is an arithmetic number, because the mean of its divisors is an integer number (5894712).

Almost surely, 2^81501673 is an apocalyptic number.

It is an amenable number.

81501673 is a deficient number, since it is larger than the sum of its proper divisors (12813719).

81501673 is a wasteful number, since it uses less digits than its factorization.

81501673 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5376.

The product of its (nonzero) digits is 5040, while the sum is 31.

The square root of 81501673 is about 9027.8277010585. The cubic root of 81501673 is about 433.5662896666.

The spelling of 81501673 in words is "eighty-one million, five hundred one thousand, six hundred seventy-three".