621838949 has 2 divisors, whose sum is σ = 621838950. Its totient is φ = 621838948.

The previous prime is 621838939. The next prime is 621838991. The reversal of 621838949 is 949838126.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 553660900 + 68178049 = 23530^2 + 8257^2 .

It is a cyclic number.

It is not a de Polignac number, because 621838949 - 2⁴ = 621838933 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 621838897 and 621838906.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (621838939) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 310919474 + 310919475.

It is an arithmetic number, because the mean of its divisors is an integer number (310919475).

Almost surely, 2^621838949 is an apocalyptic number.

It is an amenable number.

621838949 is a deficient number, since it is larger than the sum of its proper divisors (1).

621838949 is an equidigital number, since it uses as much as digits as its factorization.

621838949 is an evil number, because the sum of its binary digits is even.

The product of its digits is 746496, while the sum is 50.

The square root of 621838949 is about 24936.6988392610. The cubic root of 621838949 is about 853.5441174274.

The spelling of 621838949 in words is "six hundred twenty-one million, eight hundred thirty-eight thousand, nine hundred forty-nine".