81711164 has 12 divisors (see below), whose sum is σ = 147607488. Its totient is φ = 39537600.

The previous prime is 81711139. The next prime is 81711169. The reversal of 81711164 is 46111718.

It is a plaindrome in base 12.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81711169) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 329357 + ... + 329604.

It is an arithmetic number, because the mean of its divisors is an integer number (12300624).

Almost surely, 2^81711164 is an apocalyptic number.

It is an amenable number.

81711164 is a deficient number, since it is larger than the sum of its proper divisors (65896324).

81711164 is a wasteful number, since it uses less digits than its factorization.

81711164 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 658996 (or 658994 counting only the distinct ones).

The product of its digits is 1344, while the sum is 29.

The square root of 81711164 is about 9039.4227691817. The cubic root of 81711164 is about 433.9374498399.

The spelling of 81711164 in words is "eighty-one million, seven hundred eleven thousand, one hundred sixty-four".