81703945 has 4 divisors (see below), whose sum is σ = 98044740. Its totient is φ = 65363152.

The previous prime is 81703931. The next prime is 81703957. The reversal of 81703945 is 54930718.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 64464841 + 17239104 = 8029^2 + 4152^2 .

It is a cyclic number.

It is not a de Polignac number, because 81703945 - 2¹¹ = 81701897 is a prime.

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, 8170390 + ... + 8170399.

It is an arithmetic number, because the mean of its divisors is an integer number (24511185).

Almost surely, 2^81703945 is an apocalyptic number.

It is an amenable number.

81703945 is a deficient number, since it is larger than the sum of its proper divisors (16340795).

81703945 is a wasteful number, since it uses less digits than its factorization.

81703945 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16340794.

The product of its (nonzero) digits is 30240, while the sum is 37.

The square root of 81703945 is about 9039.0234538915. The cubic root of 81703945 is about 433.9246703267.

The spelling of 81703945 in words is "eighty-one million, seven hundred three thousand, nine hundred forty-five".