81031444402 has 16 divisors (see below), whose sum is σ = 126094679640. Its totient is φ = 39007800832.

The previous prime is 81031444387. The next prime is 81031444409. The reversal of 81031444402 is 20444413018.

It can be written as a sum of positive squares in 4 ways, for example, as 80457889801 + 573554601 = 283651^2 + 23949^2 .

It is not an unprimeable number, because it can be changed into a prime (81031444409) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1958413 + ... + 1999360.

Almost surely, 2^81031444402 is an apocalyptic number.

81031444402 is a deficient number, since it is larger than the sum of its proper divisors (45063235238).

81031444402 is a wasteful number, since it uses less digits than its factorization.

81031444402 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3958157.

The product of its (nonzero) digits is 12288, while the sum is 31.

The spelling of 81031444402 in words is "eighty-one billion, thirty-one million, four hundred forty-four thousand, four hundred two".