81833819 has 4 divisors (see below), whose sum is σ = 82986480. Its totient is φ = 80681160.

The previous prime is 81833813. The next prime is 81833863. The reversal of 81833819 is 91833818.

It is a happy number.

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 81833819 - 2¹² = 81829723 is a prime.

It is a super-2 number, since 2×81833819² = 13393547864249522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81833813) 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, 576224 + ... + 576365.

It is an arithmetic number, because the mean of its divisors is an integer number (20746620).

Almost surely, 2^81833819 is an apocalyptic number.

81833819 is a deficient number, since it is larger than the sum of its proper divisors (1152661).

81833819 is a wasteful number, since it uses less digits than its factorization.

81833819 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1152660.

The product of its digits is 41472, while the sum is 41.

The square root of 81833819 is about 9046.2046737845. The cubic root of 81833819 is about 434.1544662427.

Subtracting 81833819 from its reverse (91833818), we obtain a palindrome (9999999).

The spelling of 81833819 in words is "eighty-one million, eight hundred thirty-three thousand, eight hundred nineteen".