646523 has 2 divisors, whose sum is σ = 646524. Its totient is φ = 646522.

The previous prime is 646519. The next prime is 646537. The reversal of 646523 is 325646.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 646523 - 2² = 646519 is a prime.

It is equal to p₅₂₅₅₉ and since 646523 and 52559 have the same sum of digits, it is a Honaker prime.

It is a junction number, because it is equal to n+sod(n) for n = 646492 and 646501.

It is not a weakly prime, because it can be changed into another prime (646543) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 323261 + 323262.

It is an arithmetic number, because the mean of its divisors is an integer number (323262).

2⁶⁴⁶⁵²³ is an apocalyptic number.

646523 is a deficient number, since it is larger than the sum of its proper divisors (1).

646523 is an equidigital number, since it uses as much as digits as its factorization.

646523 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4320, while the sum is 26.

The square root of 646523 is about 804.0665395351. The cubic root of 646523 is about 86.4691772080.

The spelling of 646523 in words is "six hundred forty-six thousand, five hundred twenty-three".