621313309 has 2 divisors, whose sum is σ = 621313310. Its totient is φ = 621313308.

The previous prime is 621313289. The next prime is 621313339. The reversal of 621313309 is 903313126.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 617522500 + 3790809 = 24850^2 + 1947^2 .

It is a cyclic number.

It is not a de Polignac number, because 621313309 - 2¹¹ = 621311261 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (621313339) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 310656654 + 310656655.

It is an arithmetic number, because the mean of its divisors is an integer number (310656655).

Almost surely, 2^621313309 is an apocalyptic number.

It is an amenable number.

621313309 is a deficient number, since it is larger than the sum of its proper divisors (1).

621313309 is an equidigital number, since it uses as much as digits as its factorization.

621313309 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2916, while the sum is 28.

The square root of 621313309 is about 24926.1571245950. The cubic root of 621313309 is about 853.3035495620.

The spelling of 621313309 in words is "six hundred twenty-one million, three hundred thirteen thousand, three hundred nine".