81229469 has 4 divisors (see below), whose sum is σ = 81470844. Its totient is φ = 80988096.

The previous prime is 81229457. The next prime is 81229471. The reversal of 81229469 is 96492218.

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 29920900 + 51308569 = 5470^2 + 7163^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81229469 is a prime.

It is a super-2 number, since 2×81229469² = 13196453268043922, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81229439) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 120182 + ... + 120855.

It is an arithmetic number, because the mean of its divisors is an integer number (20367711).

Almost surely, 2^81229469 is an apocalyptic number.

It is an amenable number.

81229469 is a deficient number, since it is larger than the sum of its proper divisors (241375).

81229469 is a wasteful number, since it uses less digits than its factorization.

81229469 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 241374.

The product of its digits is 62208, while the sum is 41.

The square root of 81229469 is about 9012.7392617339. The cubic root of 81229469 is about 433.0830680483.

The spelling of 81229469 in words is "eighty-one million, two hundred twenty-nine thousand, four hundred sixty-nine".