81559305 has 48 divisors (see below), whose sum is σ = 154365120. Its totient is φ = 41197248.

The previous prime is 81559297. The next prime is 81559327. The reversal of 81559305 is 50395518.

It is a happy number.

It is not a de Polignac number, because 81559305 - 2³ = 81559297 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 81559305.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 21319 + ... + 24851.

It is an arithmetic number, because the mean of its divisors is an integer number (3215940).

Almost surely, 2^81559305 is an apocalyptic number.

It is an amenable number.

81559305 is a deficient number, since it is larger than the sum of its proper divisors (72805815).

81559305 is a wasteful number, since it uses less digits than its factorization.

81559305 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3572 (or 3560 counting only the distinct ones).

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

The square root of 81559305 is about 9031.0190454898. The cubic root of 81559305 is about 433.6684610048.

The spelling of 81559305 in words is "eighty-one million, five hundred fifty-nine thousand, three hundred five".