621040 has 40 divisors (see below), whose sum is σ = 1651680. Its totient is φ = 212736.

The previous prime is 621031. The next prime is 621043. The reversal of 621040 is 40126.

It is a tau number, because it is divible by the number of its divisors (40).

It is a self number, because there is not a number n which added to its sum of digits gives 621040.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (621043) by changing a digit.

621040 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

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 7 ways as a sum of consecutive naturals, for example, 6 + ... + 1114.

It is an arithmetic number, because the mean of its divisors is an integer number (41292).

2⁶²¹⁰⁴⁰ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 621040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (825840).

621040 is an abundant number, since it is smaller than the sum of its proper divisors (1030640).

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

621040 is a wasteful number, since it uses less digits than its factorization.

621040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1129 (or 1123 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 13.

The square root of 621040 is about 788.0609113514. The cubic root of 621040 is about 85.3178411546.

Adding to 621040 its reverse (40126), we get a palindrome (661166).

The spelling of 621040 in words is "six hundred twenty-one thousand, forty".