640463 has 2 divisors, whose sum is σ = 640464. Its totient is φ = 640462.

The previous prime is 640457. The next prime is 640477. The reversal of 640463 is 364046.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 640463 - 2¹⁰ = 639439 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (640483) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 320231 + 320232.

It is an arithmetic number, because the mean of its divisors is an integer number (320232).

2⁶⁴⁰⁴⁶³ is an apocalyptic number.

640463 is a deficient number, since it is larger than the sum of its proper divisors (1).

640463 is an equidigital number, since it uses as much as digits as its factorization.

640463 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1728, while the sum is 23.

The square root of 640463 is about 800.2893226827. The cubic root of 640463 is about 86.1981639099.

The spelling of 640463 in words is "six hundred forty thousand, four hundred sixty-three".