624221 has 4 divisors (see below), whose sum is σ = 672252. Its totient is φ = 576192.

The previous prime is 624209. The next prime is 624229. The reversal of 624221 is 122426.

624221 = T₂₀₆ + T₂₀₇ + ... + T₂₃₁.

624221 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 98596 + 525625 = 314^2 + 725^2 .

It is a cyclic number.

It is not a de Polignac number, because 624221 - 2¹⁴ = 607837 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 624221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (624229) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 23996 + ... + 24021.

It is an arithmetic number, because the mean of its divisors is an integer number (168063).

2⁶²⁴²²¹ is an apocalyptic number.

It is an amenable number.

624221 is a deficient number, since it is larger than the sum of its proper divisors (48031).

624221 is a wasteful number, since it uses less digits than its factorization.

624221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 48030.

The product of its digits is 192, while the sum is 17.

The square root of 624221 is about 790.0765785669. The cubic root of 624221 is about 85.4632606651.

Adding to 624221 its reverse (122426), we get a palindrome (746647).

The spelling of 624221 in words is "six hundred twenty-four thousand, two hundred twenty-one".