81477443 has 4 divisors (see below), whose sum is σ = 84287040. Its totient is φ = 78667848.

The previous prime is 81477437. The next prime is 81477457. The reversal of 81477443 is 34477418.

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

It is a cyclic number.

It is not a de Polignac number, because 81477443 - 2¹⁶ = 81411907 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 81477397 and 81477406.

It is not an unprimeable number, because it can be changed into a prime (81477043) 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, 1404755 + ... + 1404812.

It is an arithmetic number, because the mean of its divisors is an integer number (21071760).

Almost surely, 2^81477443 is an apocalyptic number.

81477443 is a deficient number, since it is larger than the sum of its proper divisors (2809597).

81477443 is a wasteful number, since it uses less digits than its factorization.

81477443 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2809596.

The product of its digits is 75264, while the sum is 38.

The square root of 81477443 is about 9026.4856394945. The cubic root of 81477443 is about 433.5233197821.

The spelling of 81477443 in words is "eighty-one million, four hundred seventy-seven thousand, four hundred forty-three".