81054009 has 9 divisors (see below), whose sum is σ = 117117039. Its totient is φ = 54018000.

The previous prime is 81053989. The next prime is 81054031. The reversal of 81054009 is 90045018.

The square root of 81054009 is 9003.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 43599609 + 37454400 = 6603^2 + 6120^2 .

It is a tau number, because it is divible by the number of its divisors (9).

It is not a de Polignac number, because 81054009 - 2⁷ = 81053881 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81054049) 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 8 ways as a sum of consecutive naturals, for example, 25509 + ... + 28509.

Almost surely, 2^81054009 is an apocalyptic number.

81054009 is the 9003-rd square number.

81054009 is the 4502-nd centered octagonal number.

It is an amenable number.

81054009 is a deficient number, since it is larger than the sum of its proper divisors (36063030).

81054009 is an frugal number, since it uses more digits than its factorization.

81054009 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6008 (or 3004 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 27.

The cubic root of 81054009 is about 432.7710157227.

It can be divided in two parts, 8105400 and 9, that added together give a square (8105409 = 2847²).

The spelling of 81054009 in words is "eighty-one million, fifty-four thousand, nine".