81332258 has 18 divisors (see below), whose sum is σ = 142072443.
Its totient is φ = 34818420.
The previous prime is 81332257. The next prime is 81332297. The reversal of 81332258 is 85223318.
It can be written as a sum of positive squares in only one way, i.e., 40666129 + 40666129 = 6377^2 + 6377^2
It is an ABA number since it can be written as A⋅BA, here for A=2, B=6377.
It is a super-2 number, since 2×813322582 = 13229872382757128, which contains 22 as substring.
It is a Duffinian number.
It is not an unprimeable number, because it can be changed into a prime (81332257) by changing a digit.
It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 88823 + ... + 89733.
Almost surely, 281332258 is an apocalyptic number.
81332258 is a deficient number, since it is larger than the sum of its proper divisors (60740185).
81332258 is an frugal number, since it uses more digits than its factorization.
81332258 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 1838 (or 920 counting only the distinct ones).
The product of its digits is 11520, while the sum is 32.
The square root of 81332258 is about 9018.4398872532.
The cubic root of 81332258 is about 433.2656676725.
Multiplying 81332258 by its sum of digits (32), we get a square (2602632256 = 510162).
The spelling of 81332258 in words is "eighty-one million, three hundred thirty-two thousand, two hundred fifty-eight".