81711345 has 32 divisors (see below), whose sum is σ = 133781760. Its totient is φ = 42577920.

The previous prime is 81711307. The next prime is 81711353. The reversal of 81711345 is 54311718.

It is not a de Polignac number, because 81711345 - 2⁸ = 81711089 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 129180 + ... + 129810.

It is an arithmetic number, because the mean of its divisors is an integer number (4180680).

Almost surely, 2^81711345 is an apocalyptic number.

It is an amenable number.

81711345 is a deficient number, since it is larger than the sum of its proper divisors (52070415).

81711345 is a wasteful number, since it uses less digits than its factorization.

81711345 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 825.

The product of its digits is 3360, while the sum is 30.

The square root of 81711345 is about 9039.4327808773. The cubic root of 81711345 is about 433.9377702475.

The spelling of 81711345 in words is "eighty-one million, seven hundred eleven thousand, three hundred forty-five".