621673 has 16 divisors (see below), whose sum is σ = 740880. Its totient is φ = 516096.

The previous prime is 621671. The next prime is 621679. The reversal of 621673 is 376126.

621673 = 27² + 28² + ... + 123².

It can be written as a sum of positive squares in 8 ways, for example, as 2304 + 619369 = 48^2 + 787^2 .

It is a cyclic number.

It is not a de Polignac number, because 621673 - 2¹ = 621671 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (621671) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6361 + ... + 6457.

It is an arithmetic number, because the mean of its divisors is an integer number (46305).

2⁶²¹⁶⁷³ is an apocalyptic number.

It is an amenable number.

621673 is a deficient number, since it is larger than the sum of its proper divisors (119207).

621673 is a wasteful number, since it uses less digits than its factorization.

621673 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 156.

The product of its digits is 1512, while the sum is 25.

The square root of 621673 is about 788.4624277669. The cubic root of 621673 is about 85.3468182764.

Adding to 621673 its reverse (376126), we get a palindrome (997799).

The spelling of 621673 in words is "six hundred twenty-one thousand, six hundred seventy-three".