81746280 has 256 divisors, whose sum is σ = 340070400. Its totient is φ = 16968960.

The previous prime is 81746279. The next prime is 81746309. The reversal of 81746280 is 8264718.

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, 82669 + ... + 83651.

It is an arithmetic number, because the mean of its divisors is an integer number (1328400).

Almost surely, 2^81746280 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 81746280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (170035200).

81746280 is an abundant number, since it is smaller than the sum of its proper divisors (258324120).

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

81746280 is a wasteful number, since it uses less digits than its factorization.

81746280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1021 (or 1011 counting only the distinct ones).

The product of its (nonzero) digits is 21504, while the sum is 36.

The square root of 81746280 is about 9041.3649412022. The cubic root of 81746280 is about 433.9996035872. Note that the first 3 decimals are identical.

The spelling of 81746280 in words is "eighty-one million, seven hundred forty-six thousand, two hundred eighty".