646998 has 16 divisors (see below), whose sum is σ = 1411776. Its totient is φ = 196040.

The previous prime is 646993. The next prime is 647011. The reversal of 646998 is 899646.

It is a nialpdrome in base 15.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (646991) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4836 + ... + 4967.

It is an arithmetic number, because the mean of its divisors is an integer number (88236).

2⁶⁴⁶⁹⁹⁸ is an apocalyptic number.

646998 is an abundant number, since it is smaller than the sum of its proper divisors (764778).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

646998 is a wasteful number, since it uses less digits than its factorization.

646998 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9819.

The product of its digits is 93312, while the sum is 42.

The square root of 646998 is about 804.3618588670. The cubic root of 646998 is about 86.4903483055.

The spelling of 646998 in words is "six hundred forty-six thousand, nine hundred ninety-eight".