81161026 has 12 divisors (see below), whose sum is σ = 129324978. Its totient is φ = 38193152.

The previous prime is 81160991. The next prime is 81161033. The reversal of 81161026 is 62016118.

It can be written as a sum of positive squares in 3 ways, for example, as 80910025 + 251001 = 8995^2 + 501^2 .

It is a super-2 number, since 2×81161026² = 13174224282745352, which contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 69631 + ... + 70786.

Almost surely, 2^81161026 is an apocalyptic number.

81161026 is a deficient number, since it is larger than the sum of its proper divisors (48163952).

81161026 is a wasteful number, since it uses less digits than its factorization.

81161026 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 140453 (or 140436 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 25.

The square root of 81161026 is about 9008.9414472512. The cubic root of 81161026 is about 432.9613969607.

The spelling of 81161026 in words is "eighty-one million, one hundred sixty-one thousand, twenty-six".