81267829 has 4 divisors (see below), whose sum is σ = 81343276. Its totient is φ = 81192384.

The previous prime is 81267817. The next prime is 81267881. The reversal of 81267829 is 92876218.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 72846225 + 8421604 = 8535^2 + 2902^2 .

It is a cyclic number.

It is not a de Polignac number, because 81267829 - 2¹¹ = 81265781 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 (81267229) 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, 36084 + ... + 38269.

It is an arithmetic number, because the mean of its divisors is an integer number (20335819).

Almost surely, 2^81267829 is an apocalyptic number.

It is an amenable number.

81267829 is a deficient number, since it is larger than the sum of its proper divisors (75447).

81267829 is a wasteful number, since it uses less digits than its factorization.

81267829 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 75446.

The product of its digits is 96768, while the sum is 43.

The square root of 81267829 is about 9014.8671093921. The cubic root of 81267829 is about 433.1512307166.

The spelling of 81267829 in words is "eighty-one million, two hundred sixty-seven thousand, eight hundred twenty-nine".