81447269 has 4 divisors (see below), whose sum is σ = 81609696. Its totient is φ = 81284844.

The previous prime is 81447263. The next prime is 81447271. The reversal of 81447269 is 96274418.

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 81447269 - 2¹⁶ = 81381733 is a prime.

It is a super-2 number, since 2×81447269² = 13267315255116722, 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 (81447263) 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, 80459 + ... + 81464.

It is an arithmetic number, because the mean of its divisors is an integer number (20402424).

Almost surely, 2^81447269 is an apocalyptic number.

It is an amenable number.

81447269 is a deficient number, since it is larger than the sum of its proper divisors (162427).

81447269 is a wasteful number, since it uses less digits than its factorization.

81447269 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 162426.

The product of its digits is 96768, while the sum is 41.

The square root of 81447269 is about 9024.8140701069. The cubic root of 81447269 is about 433.4697967975.

The spelling of 81447269 in words is "eighty-one million, four hundred forty-seven thousand, two hundred sixty-nine".