621216317 has 2 divisors, whose sum is σ = 621216318. Its totient is φ = 621216316.

The previous prime is 621216307. The next prime is 621216319. The reversal of 621216317 is 713612126.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 560079556 + 61136761 = 23666^2 + 7819^2 .

It is a cyclic number.

It is not a de Polignac number, because 621216317 - 2¹⁴ = 621199933 is a prime.

Together with 621216319, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 621216317.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (621216319) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 310608158 + 310608159.

It is an arithmetic number, because the mean of its divisors is an integer number (310608159).

Almost surely, 2^621216317 is an apocalyptic number.

It is an amenable number.

621216317 is a deficient number, since it is larger than the sum of its proper divisors (1).

621216317 is an equidigital number, since it uses as much as digits as its factorization.

621216317 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3024, while the sum is 29.

The square root of 621216317 is about 24924.2114619500. The cubic root of 621216317 is about 853.2591447377.

The spelling of 621216317 in words is "six hundred twenty-one million, two hundred sixteen thousand, three hundred seventeen".