81057433 has 4 divisors (see below), whose sum is σ = 81640720. Its totient is φ = 80474148.

The previous prime is 81057421. The next prime is 81057437. The reversal of 81057433 is 33475018.

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, and also an emirpimes, since its reverse is a distinct semiprime: 33475018 = 2 ⋅16737509.

It is a cyclic number.

It is not a de Polignac number, because 81057433 - 2¹⁷ = 80926361 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 81057395 and 81057404.

It is not an unprimeable number, because it can be changed into a prime (81057437) 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, 291435 + ... + 291712.

It is an arithmetic number, because the mean of its divisors is an integer number (20410180).

Almost surely, 2^81057433 is an apocalyptic number.

It is an amenable number.

81057433 is a deficient number, since it is larger than the sum of its proper divisors (583287).

81057433 is a wasteful number, since it uses less digits than its factorization.

81057433 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 583286.

The product of its (nonzero) digits is 10080, while the sum is 31.

The square root of 81057433 is about 9003.1901568277. The cubic root of 81057433 is about 432.7771095487. Note that the first 3 decimals are identical.

The spelling of 81057433 in words is "eighty-one million, fifty-seven thousand, four hundred thirty-three".