81576970 has 16 divisors (see below), whose sum is σ = 146943720. Its totient is φ = 32607424.

The previous prime is 81576967. The next prime is 81576991. The reversal of 81576970 is 7967518.

It can be written as a sum of positive squares in 4 ways, for example, as 80622441 + 954529 = 8979^2 + 977^2 .

It is an unprimeable number.

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, 21324 + ... + 24856.

Almost surely, 2^81576970 is an apocalyptic number.

81576970 is a deficient number, since it is larger than the sum of its proper divisors (65366750).

81576970 is a wasteful number, since it uses less digits than its factorization.

81576970 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5849.

The product of its (nonzero) digits is 105840, while the sum is 43.

The square root of 81576970 is about 9031.9970106284. The cubic root of 81576970 is about 433.6997682863.

The spelling of 81576970 in words is "eighty-one million, five hundred seventy-six thousand, nine hundred seventy".