81930377472 has 72 divisors (see below), whose sum is σ = 218842053696. Its totient is φ = 27211462656.

The previous prime is 81930377467. The next prime is 81930377483. The reversal of 81930377472 is 27477303918.

It is a happy number.

It is a super-2 number, since 2×81930377472² (a number of 23 digits) contains 22 as substring.

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, 20173 + ... + 405299.

It is an arithmetic number, because the mean of its divisors is an integer number (3039472968).

Almost surely, 2^81930377472 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81930377472, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (109421026848).

81930377472 is an abundant number, since it is smaller than the sum of its proper divisors (136911676224).

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

81930377472 is a wasteful number, since it uses less digits than its factorization.

81930377472 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 385423 (or 385409 counting only the distinct ones).

The product of its (nonzero) digits is 1778112, while the sum is 51.

The spelling of 81930377472 in words is "eighty-one billion, nine hundred thirty million, three hundred seventy-seven thousand, four hundred seventy-two".