621984 has 96 divisors (see below), whose sum is σ = 1935360. Its totient is φ = 172800.

The previous prime is 621983. The next prime is 621997. The reversal of 621984 is 489126.

621984 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (96).

It is not an unprimeable number, because it can be changed into a prime (621983) by changing a digit.

It is an upside-down number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 20049 + ... + 20079.

It is an arithmetic number, because the mean of its divisors is an integer number (20160).

2⁶²¹⁹⁸⁴ 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 621984, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (967680).

621984 is an abundant number, since it is smaller than the sum of its proper divisors (1313376).

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

621984 is a wasteful number, since it uses less digits than its factorization.

621984 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 74 (or 66 counting only the distinct ones).

The product of its digits is 3456, while the sum is 30.

The square root of 621984 is about 788.6596223974. The cubic root of 621984 is about 85.3610478556.

The spelling of 621984 in words is "six hundred twenty-one thousand, nine hundred eighty-four".