81499069073 has 8 divisors (see below), whose sum is σ = 81889594920. Its totient is φ = 81109192320.

The previous prime is 81499069063. The next prime is 81499069081. The reversal of 81499069073 is 37096099418.

It can be written as a sum of positive squares in 4 ways, for example, as 13949499664 + 67549569409 = 118108^2 + 259903^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 81499069073 - 2⁸ = 81499068817 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81499069033) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 90383 + ... + 413723.

It is an arithmetic number, because the mean of its divisors is an integer number (10236199365).

Almost surely, 2^81499069073 is an apocalyptic number.

It is an amenable number.

81499069073 is a deficient number, since it is larger than the sum of its proper divisors (390525847).

81499069073 is a wasteful number, since it uses less digits than its factorization.

81499069073 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 324547.

The product of its (nonzero) digits is 2939328, while the sum is 56.

The spelling of 81499069073 in words is "eighty-one billion, four hundred ninety-nine million, sixty-nine thousand, seventy-three".