81951326445 has 32 divisors (see below), whose sum is σ = 132203335680. Its totient is φ = 43347225600.

The previous prime is 81951326417. The next prime is 81951326449. The reversal of 81951326445 is 54462315918.

It is not a de Polignac number, because 81951326445 - 2⁸ = 81951326189 is a prime.

It is a Smith number, since the sum of its digits (48) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a junction number, because it is equal to n+sod(n) for n = 81951326394 and 81951326403.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81951326449) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 6602245 + ... + 6614645.

It is an arithmetic number, because the mean of its divisors is an integer number (4131354240).

Almost surely, 2^81951326445 is an apocalyptic number.

It is an amenable number.

81951326445 is a deficient number, since it is larger than the sum of its proper divisors (50252009235).

81951326445 is a wasteful number, since it uses less digits than its factorization.

81951326445 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16005.

The product of its digits is 1036800, while the sum is 48.

The spelling of 81951326445 in words is "eighty-one billion, nine hundred fifty-one million, three hundred twenty-six thousand, four hundred forty-five".