81338334628 has 12 divisors (see below), whose sum is σ = 142359949900. Its totient is φ = 40664063232.

The previous prime is 81338334599. The next prime is 81338334629. The reversal of 81338334628 is 82643383318.

It can be written as a sum of positive squares in 2 ways, for example, as 48802111744 + 32536222884 = 220912^2 + 180378^2 .

It is not an unprimeable number, because it can be changed into a prime (81338334629) 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 3 ways as a sum of consecutive naturals, for example, 1240053 + ... + 1303996.

Almost surely, 2^81338334628 is an apocalyptic number.

It is an amenable number.

81338334628 is a deficient number, since it is larger than the sum of its proper divisors (61021615272).

81338334628 is a wasteful number, since it uses less digits than its factorization.

81338334628 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2552046 (or 2552044 counting only the distinct ones).

The product of its digits is 1990656, while the sum is 49.

The spelling of 81338334628 in words is "eighty-one billion, three hundred thirty-eight million, three hundred thirty-four thousand, six hundred twenty-eight".