81680446774040 has 32 divisors (see below), whose sum is σ = 183791634277680. Its totient is φ = 32670289103232.

The previous prime is 81680446774037. The next prime is 81680446774049. The reversal of 81680446774040 is 4047764408618.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81680446774049) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 58349834 + ... + 59733273.

Almost surely, 2^{81680446774040} is an apocalyptic number.

It is an amenable number.

81680446774040 is an abundant number, since it is smaller than the sum of its proper divisors (102111187503640).

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

81680446774040 is a wasteful number, since it uses less digits than its factorization.

81680446774040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 118100411 (or 118100407 counting only the distinct ones).

The product of its (nonzero) digits is 28901376, while the sum is 59.

The spelling of 81680446774040 in words is "eighty-one trillion, six hundred eighty billion, four hundred forty-six million, seven hundred seventy-four thousand, forty".