81301566 has 16 divisors (see below), whose sum is σ = 164214288. Its totient is φ = 26832000.

The previous prime is 81301559. The next prime is 81301601. The reversal of 81301566 is 66510318.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 66475 + ... + 67686.

It is an arithmetic number, because the mean of its divisors is an integer number (10263393).

Almost surely, 2^81301566 is an apocalyptic number.

81301566 is an abundant number, since it is smaller than the sum of its proper divisors (82912722).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81301566 is a wasteful number, since it uses less digits than its factorization.

81301566 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 134267.

The product of its (nonzero) digits is 4320, while the sum is 30.

The square root of 81301566 is about 9016.7381019968. The cubic root of 81301566 is about 433.2111609562.

The spelling of 81301566 in words is "eighty-one million, three hundred one thousand, five hundred sixty-six".