81771673380 has 48 divisors (see below), whose sum is σ = 230607908160. Its totient is φ = 21648901248.

The previous prime is 81771673343. The next prime is 81771673387. The reversal of 81771673380 is 8337617718.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (81771673387) 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, 4894039 + ... + 4910718.

It is an arithmetic number, because the mean of its divisors is an integer number (4804331420).

Almost surely, 2^81771673380 is an apocalyptic number.

It is an amenable number.

81771673380 is an abundant number, since it is smaller than the sum of its proper divisors (148836234780).

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

81771673380 is a wasteful number, since it uses less digits than its factorization.

81771673380 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9804908 (or 9804906 counting only the distinct ones).

The product of its (nonzero) digits is 1185408, while the sum is 51.

The spelling of 81771673380 in words is "eighty-one billion, seven hundred seventy-one million, six hundred seventy-three thousand, three hundred eighty".