629840 has 20 divisors (see below), whose sum is σ = 1464564. Its totient is φ = 251904.

The previous prime is 629819. The next prime is 629843. The reversal of 629840 is 48926.

It can be written as a sum of positive squares in 2 ways, for example, as 99856 + 529984 = 316^2 + 728^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (629843) by changing a digit.

629840 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3857 + ... + 4016.

2⁶²⁹⁸⁴⁰ is an apocalyptic number.

It is an amenable number.

629840 is an abundant number, since it is smaller than the sum of its proper divisors (834724).

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

629840 is a wasteful number, since it uses less digits than its factorization.

629840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7886 (or 7880 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 29.

The square root of 629840 is about 793.6245963930. The cubic root of 629840 is about 85.7189309652.

The spelling of 629840 in words is "six hundred twenty-nine thousand, eight hundred forty".