81648419 has 2 divisors, whose sum is σ = 81648420. Its totient is φ = 81648418.

The previous prime is 81648403. The next prime is 81648421. The reversal of 81648419 is 91484618.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 81648419 - 2⁴ = 81648403 is a prime.

It is a super-2 number, since 2×81648419² = 13332928650399122, which contains 22 as substring.

Together with 81648421, 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 (81648499) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40824209 + 40824210.

It is an arithmetic number, because the mean of its divisors is an integer number (40824210).

Almost surely, 2^81648419 is an apocalyptic number.

81648419 is a deficient number, since it is larger than the sum of its proper divisors (1).

81648419 is an equidigital number, since it uses as much as digits as its factorization.

81648419 is an evil number, because the sum of its binary digits is even.

The product of its digits is 55296, while the sum is 41.

The square root of 81648419 is about 9035.9514717599. The cubic root of 81648419 is about 433.8263496502.

The spelling of 81648419 in words is "eighty-one million, six hundred forty-eight thousand, four hundred nineteen".