81066744 has 192 divisors, whose sum is σ = 264176640. Its totient is φ = 23016960.

The previous prime is 81066721. The next prime is 81066757. The reversal of 81066744 is 44766018.

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

It is a junction number, because it is equal to n+sod(n) for n = 81066699 and 81066708.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 363417 + ... + 363639.

It is an arithmetic number, because the mean of its divisors is an integer number (1375920).

Almost surely, 2^81066744 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 81066744, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (132088320).

81066744 is an abundant number, since it is smaller than the sum of its proper divisors (183109896).

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

81066744 is a wasteful number, since it uses less digits than its factorization.

81066744 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 272 (or 256 counting only the distinct ones).

The product of its (nonzero) digits is 32256, while the sum is 36.

The square root of 81066744 is about 9003.7072364665. The cubic root of 81066744 is about 432.7936798300.

It can be divided in two parts, 81066 and 744, that added together give a triangular number (81810 = T₄₀₄).

The spelling of 81066744 in words is "eighty-one million, sixty-six thousand, seven hundred forty-four".