81321115306 has 16 divisors (see below), whose sum is σ = 129187906560. Its totient is φ = 38259622080.

The previous prime is 81321115301. The next prime is 81321115307. The reversal of 81321115306 is 60351112318.

It is a super-2 number, since 2×81321115306² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (81321115301) 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, 140010 + ... + 426901.

It is an arithmetic number, because the mean of its divisors is an integer number (8074244160).

Almost surely, 2^81321115306 is an apocalyptic number.

81321115306 is a deficient number, since it is larger than the sum of its proper divisors (47866791254).

81321115306 is a wasteful number, since it uses less digits than its factorization.

81321115306 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 571149.

The product of its (nonzero) digits is 4320, while the sum is 31.

The spelling of 81321115306 in words is "eighty-one billion, three hundred twenty-one million, one hundred fifteen thousand, three hundred six".