646499 has 4 divisors (see below), whose sum is σ = 738864. Its totient is φ = 554136.

The previous prime is 646453. The next prime is 646519. The reversal of 646499 is 994646.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 994646 = 2 ⋅497323.

It is a cyclic number.

It is not a de Polignac number, because 646499 - 2¹² = 642403 is a prime.

It is not an unprimeable number, because it can be changed into a prime (646099) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 46172 + ... + 46185.

It is an arithmetic number, because the mean of its divisors is an integer number (184716).

2⁶⁴⁶⁴⁹⁹ is an apocalyptic number.

646499 is a deficient number, since it is larger than the sum of its proper divisors (92365).

646499 is an equidigital number, since it uses as much as digits as its factorization.

646499 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 92364.

The product of its digits is 46656, while the sum is 38.

The square root of 646499 is about 804.0516152586. The cubic root of 646499 is about 86.4681072352.

It can be divided in two parts, 6464 and 99, that multiplied together give a palindrome (639936).

The spelling of 646499 in words is "six hundred forty-six thousand, four hundred ninety-nine".