81165433 has 4 divisors (see below), whose sum is σ = 81910180. Its totient is φ = 80420688.

The previous prime is 81165431. The next prime is 81165437. The reversal of 81165433 is 33456118.

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 29942784 + 51222649 = 5472^2 + 7157^2 .

It is a cyclic number.

It is not a de Polignac number, because 81165433 - 2¹ = 81165431 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 81165395 and 81165404.

It is not an unprimeable number, because it can be changed into a prime (81165431) 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, 372210 + ... + 372427.

It is an arithmetic number, because the mean of its divisors is an integer number (20477545).

Almost surely, 2^81165433 is an apocalyptic number.

It is an amenable number.

81165433 is a deficient number, since it is larger than the sum of its proper divisors (744747).

81165433 is a wasteful number, since it uses less digits than its factorization.

81165433 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 744746.

The product of its digits is 8640, while the sum is 31.

The square root of 81165433 is about 9009.1860342652. The cubic root of 81165433 is about 432.9692333424.

The spelling of 81165433 in words is "eighty-one million, one hundred sixty-five thousand, four hundred thirty-three".