6440629 has 4 divisors (see below), whose sum is σ = 6936076. Its totient is φ = 5945184.

The previous prime is 6440587. The next prime is 6440641. The reversal of 6440629 is 9260446.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 324900 + 6115729 = 570^2 + 2473^2 .

It is a cyclic number.

It is not a de Polignac number, because 6440629 - 2¹¹ = 6438581 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 6440629.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6440699) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 247704 + ... + 247729.

It is an arithmetic number, because the mean of its divisors is an integer number (1734019).

Almost surely, 2^6440629 is an apocalyptic number.

It is an amenable number.

6440629 is a deficient number, since it is larger than the sum of its proper divisors (495447).

6440629 is a wasteful number, since it uses less digits than its factorization.

6440629 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 495446.

The product of its (nonzero) digits is 10368, while the sum is 31.

The square root of 6440629 is about 2537.8394354253. The cubic root of 6440629 is about 186.0556063750.

The spelling of 6440629 in words is "six million, four hundred forty thousand, six hundred twenty-nine".