81450081 has 12 divisors (see below), whose sum is σ = 118180608. Its totient is φ = 54055224.

The previous prime is 81450073. The next prime is 81450119. The reversal of 81450081 is 18005418.

81450081 is a `hidden beast` number, since 81 + 4 + 500 + 81 = 666.

It is not a de Polignac number, because 81450081 - 2³ = 81450073 is a prime.

It is a super-2 number, since 2×81450081² = 13268231389813122, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (81450001) by changing a digit.

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 11 ways as a sum of consecutive naturals, for example, 18285 + ... + 22298.

It is an arithmetic number, because the mean of its divisors is an integer number (9848384).

Almost surely, 2^81450081 is an apocalyptic number.

It is an amenable number.

81450081 is a deficient number, since it is larger than the sum of its proper divisors (36730527).

81450081 is a wasteful number, since it uses less digits than its factorization.

81450081 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40812 (or 40809 counting only the distinct ones).

The product of its (nonzero) digits is 1280, while the sum is 27.

The square root of 81450081 is about 9024.9698614455. The cubic root of 81450081 is about 433.4747853136.

Adding to 81450081 its reverse (18005418), we get a palindrome (99455499).

The spelling of 81450081 in words is "eighty-one million, four hundred fifty thousand, eighty-one".