81003776 has 72 divisors (see below), whose sum is σ = 195733440. Its totient is φ = 32661504.

The previous prime is 81003763. The next prime is 81003781. The reversal of 81003776 is 67730018.

It is a happy number.

It is a super-2 number, since 2×81003776² = 13123223452516352, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (32).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 29135 + ... + 31793.

It is an arithmetic number, because the mean of its divisors is an integer number (2718520).

Almost surely, 2^81003776 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 81003776, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (97866720).

81003776 is an abundant number, since it is smaller than the sum of its proper divisors (114729664).

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

81003776 is a wasteful number, since it uses less digits than its factorization.

81003776 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2699 (or 2685 counting only the distinct ones).

The product of its (nonzero) digits is 7056, while the sum is 32.

The square root of 81003776 is about 9000.2097753330. The cubic root of 81003776 is about 432.6815943635.

The spelling of 81003776 in words is "eighty-one million, three thousand, seven hundred seventy-six".