81455125 has 8 divisors (see below), whose sum is σ = 101656152. Its totient is φ = 65164000.

The previous prime is 81455111. The next prime is 81455161. The reversal of 81455125 is 52155418.

It can be written as a sum of positive squares in 4 ways, for example, as 8625969 + 72829156 = 2937^2 + 8534^2 .

It is not a de Polignac number, because 81455125 - 2²¹ = 79357973 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 325696 + ... + 325945.

It is an arithmetic number, because the mean of its divisors is an integer number (12707019).

Almost surely, 2^81455125 is an apocalyptic number.

It is an amenable number.

81455125 is a deficient number, since it is larger than the sum of its proper divisors (20201027).

81455125 is an equidigital number, since it uses as much as digits as its factorization.

81455125 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 651656 (or 651646 counting only the distinct ones).

The product of its digits is 8000, while the sum is 31.

The square root of 81455125 is about 9025.2493040359. The cubic root of 81455125 is about 433.4837331323.

The spelling of 81455125 in words is "eighty-one million, four hundred fifty-five thousand, one hundred twenty-five".