621730 has 16 divisors (see below), whose sum is σ = 1134720. Its totient is φ = 245232.

The previous prime is 621721. The next prime is 621739. The reversal of 621730 is 37126.

621730 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (621721) and next prime (621739).

It is a junction number, because it is equal to n+sod(n) for n = 621698 and 621707.

It is not an unprimeable number, because it can be changed into a prime (621739) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 397 + ... + 1183.

It is an arithmetic number, because the mean of its divisors is an integer number (70920).

2⁶²¹⁷³⁰ is an apocalyptic number.

621730 is a deficient number, since it is larger than the sum of its proper divisors (512990).

621730 is a wasteful number, since it uses less digits than its factorization.

621730 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 873.

The product of its (nonzero) digits is 252, while the sum is 19.

The square root of 621730 is about 788.4985732390. The cubic root of 621730 is about 85.3494266251.

Adding to 621730 its reverse (37126), we get a palindrome (658856).

It can be divided in two parts, 6 and 21730, that added together give a triangular number (21736 = T₂₀₈).

The spelling of 621730 in words is "six hundred twenty-one thousand, seven hundred thirty".