81157522 has 16 divisors (see below), whose sum is σ = 124335000. Its totient is φ = 39716352.

The previous prime is 81157487. The next prime is 81157523. The reversal of 81157522 is 22575118.

It can be written as a sum of positive squares in 4 ways, for example, as 48427681 + 32729841 = 6959^2 + 5721^2 .

It is not an unprimeable number, because it can be changed into a prime (81157523) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 64354 + ... + 65602.

Almost surely, 2^81157522 is an apocalyptic number.

81157522 is a deficient number, since it is larger than the sum of its proper divisors (43177478).

81157522 is a wasteful number, since it uses less digits than its factorization.

81157522 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1917.

The product of its digits is 5600, while the sum is 31.

The square root of 81157522 is about 9008.7469716937. The cubic root of 81157522 is about 432.9551660613.

The spelling of 81157522 in words is "eighty-one million, one hundred fifty-seven thousand, five hundred twenty-two".