81353819 has 2 divisors, whose sum is σ = 81353820. Its totient is φ = 81353818.

The previous prime is 81353791. The next prime is 81353821. The reversal of 81353819 is 91835318.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 81353819 - 2²⁰ = 80305243 is a prime.

It is a super-2 number, since 2×81353819² = 13236887731769522, which contains 22 as substring.

Together with 81353821, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (81353719) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40676909 + 40676910.

It is an arithmetic number, because the mean of its divisors is an integer number (40676910).

Almost surely, 2^81353819 is an apocalyptic number.

81353819 is a deficient number, since it is larger than the sum of its proper divisors (1).

81353819 is an equidigital number, since it uses as much as digits as its factorization.

81353819 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 25920, while the sum is 38.

The square root of 81353819 is about 9019.6351921793. The cubic root of 81353819 is about 433.3039502102.

The spelling of 81353819 in words is "eighty-one million, three hundred fifty-three thousand, eight hundred nineteen".