81969159776 has 96 divisors (see below), whose sum is σ = 202578485760. Its totient is φ = 31833686016.

The previous prime is 81969159773. The next prime is 81969159817. The reversal of 81969159776 is 67795196918.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81969159773) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 320801 + ... + 516576.

It is an arithmetic number, because the mean of its divisors is an integer number (2110192560).

Almost surely, 2^81969159776 is an apocalyptic number.

It is an amenable number.

81969159776 is an abundant number, since it is smaller than the sum of its proper divisors (120609325984).

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

81969159776 is a wasteful number, since it uses less digits than its factorization.

81969159776 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 837436 (or 837428 counting only the distinct ones).

The product of its digits is 51438240, while the sum is 68.

The spelling of 81969159776 in words is "eighty-one billion, nine hundred sixty-nine million, one hundred fifty-nine thousand, seven hundred seventy-six".