81038722 has 4 divisors (see below), whose sum is σ = 121558086. Its totient is φ = 40519360.

The previous prime is 81038717. The next prime is 81038723. The reversal of 81038722 is 22783018.

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

It can be written as a sum of positive squares in only one way, i.e., 47734281 + 33304441 = 6909^2 + 5771^2 .

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (81038723) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20259679 + ... + 20259682.

Almost surely, 2^81038722 is an apocalyptic number.

81038722 is a deficient number, since it is larger than the sum of its proper divisors (40519364).

81038722 is a wasteful number, since it uses less digits than its factorization.

81038722 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40519363.

The product of its (nonzero) digits is 5376, while the sum is 31.

The square root of 81038722 is about 9002.1509651860. The cubic root of 81038722 is about 432.7438067602.

The spelling of 81038722 in words is "eighty-one million, thirty-eight thousand, seven hundred twenty-two".