646629 has 16 divisors (see below), whose sum is σ = 944640. Its totient is φ = 391680.

The previous prime is 646619. The next prime is 646631. The reversal of 646629 is 926646.

It is not a de Polignac number, because 646629 - 2¹² = 642533 is a prime.

It is a d-powerful number, because it can be written as 6² + 4⁷ + 6³ + 6⁶ + 2¹⁹ + 9⁵ .

It is a self number, because there is not a number n which added to its sum of digits gives 646629.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (646609) 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 15 ways as a sum of consecutive naturals, for example, 1377 + ... + 1785.

It is an arithmetic number, because the mean of its divisors is an integer number (59040).

2⁶⁴⁶⁶²⁹ is an apocalyptic number.

It is an amenable number.

646629 is a deficient number, since it is larger than the sum of its proper divisors (298011).

646629 is a wasteful number, since it uses less digits than its factorization.

646629 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 460.

The product of its digits is 15552, while the sum is 33.

The square root of 646629 is about 804.1324517764. The cubic root of 646629 is about 86.4739026041.

It can be divided in two parts, 646 and 629, that added together give a triangular number (1275 = T₅₀).

The spelling of 646629 in words is "six hundred forty-six thousand, six hundred twenty-nine".