81366071 has 16 divisors (see below), whose sum is σ = 86676480. Its totient is φ = 76275360.

The previous prime is 81366067. The next prime is 81366091. The reversal of 81366071 is 17066318.

It is not a de Polignac number, because 81366071 - 2² = 81366067 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 (81366011) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 123140 + ... + 123798.

It is an arithmetic number, because the mean of its divisors is an integer number (5417280).

Almost surely, 2^81366071 is an apocalyptic number.

81366071 is a deficient number, since it is larger than the sum of its proper divisors (5310409).

81366071 is a wasteful number, since it uses less digits than its factorization.

81366071 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 814.

The product of its (nonzero) digits is 6048, while the sum is 32.

The square root of 81366071 is about 9020.3143515068. The cubic root of 81366071 is about 433.3257011805.

The spelling of 81366071 in words is "eighty-one million, three hundred sixty-six thousand, seventy-one".