81004771 has 8 divisors (see below), whose sum is σ = 85360320. Its totient is φ = 76658472.

The previous prime is 81004769. The next prime is 81004837. The reversal of 81004771 is 17740018.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 81004771 - 2¹ = 81004769 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81004751) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 22716 + ... + 26038.

It is an arithmetic number, because the mean of its divisors is an integer number (10670040).

Almost surely, 2^81004771 is an apocalyptic number.

81004771 is a deficient number, since it is larger than the sum of its proper divisors (4355549).

81004771 is a wasteful number, since it uses less digits than its factorization.

81004771 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4625.

The product of its (nonzero) digits is 1568, while the sum is 28.

The square root of 81004771 is about 9000.2650516526. The cubic root of 81004771 is about 432.6833659535.

Adding to 81004771 its reverse (17740018), we get a palindrome (98744789).

The spelling of 81004771 in words is "eighty-one million, four thousand, seven hundred seventy-one".