81955305 has 24 divisors (see below), whose sum is σ = 146956680. Its totient is φ = 42201600.

The previous prime is 81955297. The next prime is 81955343. The reversal of 81955305 is 50355918.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 522729 + 81432576 = 723^2 + 9024^2 .

It is not a de Polignac number, because 81955305 - 2³ = 81955297 is a prime.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 81955305.

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 23 ways as a sum of consecutive naturals, for example, 30096 + ... + 32705.

It is an arithmetic number, because the mean of its divisors is an integer number (6123195).

Almost surely, 2^81955305 is an apocalyptic number.

It is an amenable number.

81955305 is a deficient number, since it is larger than the sum of its proper divisors (65001375).

81955305 is a wasteful number, since it uses less digits than its factorization.

81955305 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 62841 (or 62838 counting only the distinct ones).

The product of its (nonzero) digits is 27000, while the sum is 36.

The square root of 81955305 is about 9052.9169332321. The cubic root of 81955305 is about 434.3692006541.

The spelling of 81955305 in words is "eighty-one million, nine hundred fifty-five thousand, three hundred five".