684655123 has 2 divisors, whose sum is σ = 684655124. Its totient is φ = 684655122.

The previous prime is 684655109. The next prime is 684655163. The reversal of 684655123 is 321556486.

It is an a-pointer prime, because the next prime (684655163) can be obtained adding 684655123 to its sum of digits (40).

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 684655123 - 2⁵ = 684655091 is a prime.

It is not a weakly prime, because it can be changed into another prime (684655163) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 342327561 + 342327562.

It is an arithmetic number, because the mean of its divisors is an integer number (342327562).

Almost surely, 2^684655123 is an apocalyptic number.

684655123 is a deficient number, since it is larger than the sum of its proper divisors (1).

684655123 is an equidigital number, since it uses as much as digits as its factorization.

684655123 is an evil number, because the sum of its binary digits is even.

The product of its digits is 172800, while the sum is 40.

The square root of 684655123 is about 26165.9152906983. The cubic root of 684655123 is about 881.3680181428.

The spelling of 684655123 in words is "six hundred eighty-four million, six hundred fifty-five thousand, one hundred twenty-three".