81963745 has 16 divisors (see below), whose sum is σ = 100017792. Its totient is φ = 64471680.

The previous prime is 81963727. The next prime is 81963751. The reversal of 81963745 is 54736918.

It is not a de Polignac number, because 81963745 - 2¹³ = 81955553 is a prime.

It is a Duffinian number.

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 15 ways as a sum of consecutive naturals, for example, 129580 + ... + 130210.

It is an arithmetic number, because the mean of its divisors is an integer number (6251112).

Almost surely, 2^81963745 is an apocalyptic number.

It is an amenable number.

81963745 is a deficient number, since it is larger than the sum of its proper divisors (18054047).

81963745 is a wasteful number, since it uses less digits than its factorization.

81963745 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1032.

The product of its digits is 181440, while the sum is 43.

The square root of 81963745 is about 9053.3830693283. The cubic root of 81963745 is about 434.3841110178.

The spelling of 81963745 in words is "eighty-one million, nine hundred sixty-three thousand, seven hundred forty-five".