621491659 has 2 divisors, whose sum is σ = 621491660. Its totient is φ = 621491658.

The previous prime is 621491623. The next prime is 621491677. The reversal of 621491659 is 956194126.

621491659 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 is a cyclic number.

It is not a de Polignac number, because 621491659 - 2⁹ = 621491147 is a prime.

It is not a weakly prime, because it can be changed into another prime (621491699) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 310745829 + 310745830.

It is an arithmetic number, because the mean of its divisors is an integer number (310745830).

Almost surely, 2^621491659 is an apocalyptic number.

621491659 is a deficient number, since it is larger than the sum of its proper divisors (1).

621491659 is an equidigital number, since it uses as much as digits as its factorization.

621491659 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 116640, while the sum is 43.

The square root of 621491659 is about 24929.7344350075. The cubic root of 621491659 is about 853.3851896011.

The spelling of 621491659 in words is "six hundred twenty-one million, four hundred ninety-one thousand, six hundred fifty-nine".