81005465 has 16 divisors (see below), whose sum is σ = 99532800. Its totient is φ = 63266112.

The previous prime is 81005453. The next prime is 81005467. The reversal of 81005465 is 56450018.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 81005465 - 2⁶ = 81005401 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81005467) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 62696 + ... + 63974.

It is an arithmetic number, because the mean of its divisors is an integer number (6220800).

Almost surely, 2^81005465 is an apocalyptic number.

It is an amenable number.

81005465 is a deficient number, since it is larger than the sum of its proper divisors (18527335).

81005465 is a wasteful number, since it uses less digits than its factorization.

81005465 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1576.

The product of its (nonzero) digits is 4800, while the sum is 29.

The square root of 81005465 is about 9000.3036059902. The cubic root of 81005465 is about 432.6846016066.

The spelling of 81005465 in words is "eighty-one million, five thousand, four hundred sixty-five".