81712570 has 16 divisors (see below), whose sum is σ = 147186720. Its totient is φ = 32661904.

The previous prime is 81712567. The next prime is 81712577. The reversal of 81712570 is 7521718.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (81712577) 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, 22929 + ... + 26251.

It is an arithmetic number, because the mean of its divisors is an integer number (9199170).

Almost surely, 2^81712570 is an apocalyptic number.

81712570 is a deficient number, since it is larger than the sum of its proper divisors (65474150).

81712570 is a wasteful number, since it uses less digits than its factorization.

81712570 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5789.

The product of its (nonzero) digits is 3920, while the sum is 31.

The square root of 81712570 is about 9039.5005392997. The cubic root of 81712570 is about 433.9399387391.

The spelling of 81712570 in words is "eighty-one million, seven hundred twelve thousand, five hundred seventy".