81248819 has 2 divisors, whose sum is σ = 81248820. Its totient is φ = 81248818.

The previous prime is 81248789. The next prime is 81248833. The reversal of 81248819 is 91884218.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 81248819 - 2¹⁶ = 81183283 is a prime.

It is a super-2 number, since 2×81248819² = 13202741177789522, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (81248879) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40624409 + 40624410.

It is an arithmetic number, because the mean of its divisors is an integer number (40624410).

Almost surely, 2^81248819 is an apocalyptic number.

81248819 is a deficient number, since it is larger than the sum of its proper divisors (1).

81248819 is an equidigital number, since it uses as much as digits as its factorization.

81248819 is an evil number, because the sum of its binary digits is even.

The product of its digits is 36864, while the sum is 41.

The square root of 81248819 is about 9013.8126783287. The cubic root of 81248819 is about 433.1174541405.

The spelling of 81248819 in words is "eighty-one million, two hundred forty-eight thousand, eight hundred nineteen".