81054481 has 4 divisors (see below), whose sum is σ = 81079092. Its totient is φ = 81029872.

The previous prime is 81054469. The next prime is 81054509. The reversal of 81054481 is 18445018.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 69555600 + 11498881 = 8340^2 + 3391^2 .

It is a cyclic number.

It is not a de Polignac number, because 81054481 - 2⁷ = 81054353 is a prime.

It is a super-2 number, since 2×81054481² = 13139657780358722, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81054401) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6430 + ... + 14263.

It is an arithmetic number, because the mean of its divisors is an integer number (20269773).

Almost surely, 2^81054481 is an apocalyptic number.

It is an amenable number.

81054481 is a deficient number, since it is larger than the sum of its proper divisors (24611).

81054481 is a wasteful number, since it uses less digits than its factorization.

81054481 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24610.

The product of its (nonzero) digits is 5120, while the sum is 31.

The square root of 81054481 is about 9003.0262134462. The cubic root of 81054481 is about 432.7718557697.

Adding to 81054481 its reverse (18445018), we get a palindrome (99499499).

The spelling of 81054481 in words is "eighty-one million, fifty-four thousand, four hundred eighty-one".