81740880 has 320 divisors, whose sum is σ = 314979840. Its totient is φ = 19353600.

The previous prime is 81740861. The next prime is 81740891. The reversal of 81740880 is 8804718.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1151245 + ... + 1151315.

It is an arithmetic number, because the mean of its divisors is an integer number (984312).

Almost surely, 2^81740880 is an apocalyptic number.

81740880 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81740880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (157489920).

81740880 is an abundant number, since it is smaller than the sum of its proper divisors (233238960).

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

81740880 is a wasteful number, since it uses less digits than its factorization.

81740880 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 147 (or 135 counting only the distinct ones).

The product of its (nonzero) digits is 14336, while the sum is 36.

The square root of 81740880 is about 9041.0663087934. The cubic root of 81740880 is about 433.9900469873.

The spelling of 81740880 in words is "eighty-one million, seven hundred forty thousand, eight hundred eighty".