81579004 has 24 divisors (see below), whose sum is σ = 154671440. Its totient is φ = 37647792.

The previous prime is 81578963. The next prime is 81579007. The reversal of 81579004 is 40097518.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81579007) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4147 + ... + 13429.

Almost surely, 2^81579004 is an apocalyptic number.

It is an amenable number.

81579004 is a deficient number, since it is larger than the sum of its proper divisors (73092436).

81579004 is a wasteful number, since it uses less digits than its factorization.

81579004 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9326 (or 9298 counting only the distinct ones).

The product of its (nonzero) digits is 10080, while the sum is 34.

The square root of 81579004 is about 9032.1096096095. The cubic root of 81579004 is about 433.7033728085.

It can be divided in two parts, 8157 and 9004, that added together give a square (17161 = 131²).

The spelling of 81579004 in words is "eighty-one million, five hundred seventy-nine thousand, four".