81156821330 has 32 divisors (see below), whose sum is σ = 158261451264. Its totient is φ = 29786152896.

The previous prime is 81156821323. The next prime is 81156821357. The reversal of 81156821330 is 3312865118.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 1847402 + ... + 1890821.

It is an arithmetic number, because the mean of its divisors is an integer number (4945670352).

Almost surely, 2^81156821330 is an apocalyptic number.

81156821330 is a deficient number, since it is larger than the sum of its proper divisors (77104629934).

81156821330 is a wasteful number, since it uses less digits than its factorization.

81156821330 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3738410.

The product of its (nonzero) digits is 34560, while the sum is 38.

The spelling of 81156821330 in words is "eighty-one billion, one hundred fifty-six million, eight hundred twenty-one thousand, three hundred thirty".