621663 has 12 divisors (see below), whose sum is σ = 964440. Its totient is φ = 355152.

The previous prime is 621641. The next prime is 621671. The reversal of 621663 is 366126.

It is not a de Polignac number, because 621663 - 2⁵ = 621631 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (620663) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1968 + ... + 2261.

It is an arithmetic number, because the mean of its divisors is an integer number (80370).

2⁶²¹⁶⁶³ is an apocalyptic number.

621663 is a deficient number, since it is larger than the sum of its proper divisors (342777).

621663 is a wasteful number, since it uses less digits than its factorization.

621663 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4246 (or 4239 counting only the distinct ones).

The product of its digits is 1296, while the sum is 24.

The square root of 621663 is about 788.4560862851. The cubic root of 621663 is about 85.3463606549.

Adding to 621663 its reverse (366126), we get a palindrome (987789).

The spelling of 621663 in words is "six hundred twenty-one thousand, six hundred sixty-three".