621723 has 4 divisors (see below), whose sum is σ = 828968. Its totient is φ = 414480.

The previous prime is 621721. The next prime is 621739. The reversal of 621723 is 327126.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 621723 - 2¹ = 621721 is a prime.

It is a D-number.

It is a Duffinian number.

It is a nialpdrome in base 15.

It is a self number, because there is not a number n which added to its sum of digits gives 621723.

It is not an unprimeable number, because it can be changed into a prime (621721) 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, 103618 + ... + 103623.

It is an arithmetic number, because the mean of its divisors is an integer number (207242).

2⁶²¹⁷²³ is an apocalyptic number.

621723 is a deficient number, since it is larger than the sum of its proper divisors (207245).

621723 is a wasteful number, since it uses less digits than its factorization.

621723 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 207244.

The product of its digits is 504, while the sum is 21.

The square root of 621723 is about 788.4941344106. The cubic root of 621723 is about 85.3491063102.

Adding to 621723 its reverse (327126), we get a palindrome (948849).

The spelling of 621723 in words is "six hundred twenty-one thousand, seven hundred twenty-three".