621623 has 4 divisors (see below), whose sum is σ = 654360. Its totient is φ = 588888.

The previous prime is 621619. The next prime is 621629. The reversal of 621623 is 326126.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 326126 = 2 ⋅163063.

It is a cyclic number.

It is not a de Polignac number, because 621623 - 2² = 621619 is a prime.

It is a plaindrome in base 14.

It is a junction number, because it is equal to n+sod(n) for n = 621595 and 621604.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (621629) 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, 16340 + ... + 16377.

It is an arithmetic number, because the mean of its divisors is an integer number (163590).

2⁶²¹⁶²³ is an apocalyptic number.

621623 is a deficient number, since it is larger than the sum of its proper divisors (32737).

621623 is a wasteful number, since it uses less digits than its factorization.

621623 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32736.

The product of its digits is 432, while the sum is 20.

The square root of 621623 is about 788.4307198480. The cubic root of 621623 is about 85.3445301199.

Adding to 621623 its reverse (326126), we get a palindrome (947749).

The spelling of 621623 in words is "six hundred twenty-one thousand, six hundred twenty-three".