684499919 has 2 divisors, whose sum is σ = 684499920. Its totient is φ = 684499918.

The previous prime is 684499897. The next prime is 684499957. The reversal of 684499919 is 919994486.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 684499919 - 2²⁰ = 683451343 is a prime.

It is a super-2 number, since 2×684499919² = 937080278222013122, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (684499969) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 342249959 + 342249960.

It is an arithmetic number, because the mean of its divisors is an integer number (342249960).

Almost surely, 2^684499919 is an apocalyptic number.

684499919 is a deficient number, since it is larger than the sum of its proper divisors (1).

684499919 is an equidigital number, since it uses as much as digits as its factorization.

684499919 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5038848, while the sum is 59.

The square root of 684499919 is about 26162.9493559117. The cubic root of 684499919 is about 881.3014142060.

The spelling of 684499919 in words is "six hundred eighty-four million, four hundred ninety-nine thousand, nine hundred nineteen".