81648125 has 30 divisors (see below), whose sum is σ = 110622402. Its totient is φ = 60216000.

The previous prime is 81648121. The next prime is 81648131. The reversal of 81648125 is 52184618.

It can be written as a sum of positive squares in 15 ways, for example, as 59567524 + 22080601 = 7718^2 + 4699^2 .

It is not a de Polignac number, because 81648125 - 2² = 81648121 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81648121) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 29 ways as a sum of consecutive naturals, for example, 105239 + ... + 106011.

Almost surely, 2^81648125 is an apocalyptic number.

It is an amenable number.

81648125 is a deficient number, since it is larger than the sum of its proper divisors (28974277).

81648125 is an equidigital number, since it uses as much as digits as its factorization.

81648125 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 819 (or 791 counting only the distinct ones).

The product of its digits is 15360, while the sum is 35.

The square root of 81648125 is about 9035.9352033976. The cubic root of 81648125 is about 433.8258289416.

The spelling of 81648125 in words is "eighty-one million, six hundred forty-eight thousand, one hundred twenty-five".