621617 has 2 divisors, whose sum is σ = 621618. Its totient is φ = 621616.

The previous prime is 621611. The next prime is 621619. The reversal of 621617 is 716126.

621617 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 312481 + 309136 = 559^2 + 556^2 .

It is a cyclic number.

It is not a de Polignac number, because 621617 - 2¹² = 617521 is a prime.

Together with 621619, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 621592 and 621601.

It is not a weakly prime, because it can be changed into another prime (621611) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 310808 + 310809.

It is an arithmetic number, because the mean of its divisors is an integer number (310809).

2⁶²¹⁶¹⁷ is an apocalyptic number.

It is an amenable number.

621617 is a deficient number, since it is larger than the sum of its proper divisors (1).

621617 is an equidigital number, since it uses as much as digits as its factorization.

621617 is an evil number, because the sum of its binary digits is even.

The product of its digits is 504, while the sum is 23.

The square root of 621617 is about 788.4269148120. The cubic root of 621617 is about 85.3442555328.

The spelling of 621617 in words is "six hundred twenty-one thousand, six hundred seventeen".