621869 has 2 divisors, whose sum is σ = 621870. Its totient is φ = 621868.

The previous prime is 621833. The next prime is 621871. The reversal of 621869 is 968126.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 619369 + 2500 = 787^2 + 50^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-621869 is a prime.

It is a super-2 number, since 2×621869² = 773442106322, which contains 22 as substring.

Together with 621871, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (621769) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 310934 + 310935.

It is an arithmetic number, because the mean of its divisors is an integer number (310935).

2⁶²¹⁸⁶⁹ is an apocalyptic number.

It is an amenable number.

621869 is a deficient number, since it is larger than the sum of its proper divisors (1).

621869 is an equidigital number, since it uses as much as digits as its factorization.

621869 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5184, while the sum is 32.

The square root of 621869 is about 788.5867105144. The cubic root of 621869 is about 85.3557866669.

The spelling of 621869 in words is "six hundred twenty-one thousand, eight hundred sixty-nine".