621605791 has 2 divisors, whose sum is σ = 621605792. Its totient is φ = 621605790.

The previous prime is 621605773. The next prime is 621605839. The reversal of 621605791 is 197506126.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 621605791 - 2⁵ = 621605759 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 621605791.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (621605701) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 310802895 + 310802896.

It is an arithmetic number, because the mean of its divisors is an integer number (310802896).

Almost surely, 2^621605791 is an apocalyptic number.

621605791 is a deficient number, since it is larger than the sum of its proper divisors (1).

621605791 is an equidigital number, since it uses as much as digits as its factorization.

621605791 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 22680, while the sum is 37.

The square root of 621605791 is about 24932.0234036470. The cubic root of 621605791 is about 853.4374255378.

The spelling of 621605791 in words is "six hundred twenty-one million, six hundred five thousand, seven hundred ninety-one".