620840 has 64 divisors (see below), whose sum is σ = 1632960. Its totient is φ = 209920.

The previous prime is 620831. The next prime is 620849. The reversal of 620840 is 48026.

It is an interprime number because it is at equal distance from previous prime (620831) and next prime (620849).

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a plaindrome in base 14.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (620849) by changing a digit.

620840 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 15 ways as a sum of consecutive naturals, for example, 7439 + ... + 7521.

It is an arithmetic number, because the mean of its divisors is an integer number (25515).

2⁶²⁰⁸⁴⁰ 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 620840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (816480).

620840 is an abundant number, since it is smaller than the sum of its proper divisors (1012120).

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

620840 is a wasteful number, since it uses less digits than its factorization.

620840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 122 (or 118 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 20.

The square root of 620840 is about 787.9340073889. The cubic root of 620840 is about 85.3086815727.

Adding to 620840 its reverse (48026), we get a palindrome (668866).

The spelling of 620840 in words is "six hundred twenty thousand, eight hundred forty".