81167122570 has 16 divisors (see below), whose sum is σ = 146620757448. Its totient is φ = 32351307520.

The previous prime is 81167122529. The next prime is 81167122627. The reversal of 81167122570 is 7522176118.

It can be written as a sum of positive squares in 4 ways, for example, as 55320451209 + 25846671361 = 235203^2 + 160769^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 14439739 + ... + 14445358.

Almost surely, 2^81167122570 is an apocalyptic number.

81167122570 is a deficient number, since it is larger than the sum of its proper divisors (65453634878).

81167122570 is a wasteful number, since it uses less digits than its factorization.

81167122570 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28885385.

The product of its (nonzero) digits is 47040, while the sum is 40.

Adding to 81167122570 its reverse (7522176118), we get a palindrome (88689298688).

The spelling of 81167122570 in words is "eighty-one billion, one hundred sixty-seven million, one hundred twenty-two thousand, five hundred seventy".