81711229 has 4 divisors (see below), whose sum is σ = 86011840. Its totient is φ = 77410620.

The previous prime is 81711221. The next prime is 81711233. The reversal of 81711229 is 92211718.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 81711229 - 2³ = 81711221 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 81711229.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81711221) 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, 2150277 + ... + 2150314.

It is an arithmetic number, because the mean of its divisors is an integer number (21502960).

Almost surely, 2^81711229 is an apocalyptic number.

It is an amenable number.

81711229 is a deficient number, since it is larger than the sum of its proper divisors (4300611).

81711229 is a wasteful number, since it uses less digits than its factorization.

81711229 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4300610.

The product of its digits is 2016, while the sum is 31.

The square root of 81711229 is about 9039.4263645433. The cubic root of 81711229 is about 433.9375649035.

The spelling of 81711229 in words is "eighty-one million, seven hundred eleven thousand, two hundred twenty-nine".