81645772067142 has 16 divisors (see below), whose sum is σ = 163292314852080. Its totient is φ = 27215128902752.

The previous prime is 81645772067087. The next prime is 81645772067191. The reversal of 81645772067142 is 24176027754618.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 30731517 + ... + 33282392.

It is an arithmetic number, because the mean of its divisors is an integer number (10205769678255).

Almost surely, 2^{81645772067142} is an apocalyptic number.

81645772067142 is an abundant number, since it is smaller than the sum of its proper divisors (81646542784938).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81645772067142 is a wasteful number, since it uses less digits than its factorization.

81645772067142 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 64226487.

The product of its (nonzero) digits is 31610880, while the sum is 60.

The spelling of 81645772067142 in words is "eighty-one trillion, six hundred forty-five billion, seven hundred seventy-two million, sixty-seven thousand, one hundred forty-two".