81579634 has 12 divisors (see below), whose sum is σ = 129651354. Its totient is φ = 38365632.

The previous prime is 81579629. The next prime is 81579653. The reversal of 81579634 is 43697518.

It can be written as a sum of positive squares in 3 ways, for example, as 68641225 + 12938409 = 8285^2 + 3597^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 51892 + ... + 53440.

Almost surely, 2^81579634 is an apocalyptic number.

81579634 is a deficient number, since it is larger than the sum of its proper divisors (48071720).

81579634 is an equidigital number, since it uses as much as digits as its factorization.

81579634 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3117 (or 1568 counting only the distinct ones).

The product of its digits is 181440, while the sum is 43.

The square root of 81579634 is about 9032.1444851154. The cubic root of 81579634 is about 433.7044892412.

The spelling of 81579634 in words is "eighty-one million, five hundred seventy-nine thousand, six hundred thirty-four".