621606691 has 2 divisors, whose sum is σ = 621606692. Its totient is φ = 621606690.

The previous prime is 621606613. The next prime is 621606701. The reversal of 621606691 is 196606126.

621606691 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 621606691 - 2¹⁷ = 621475619 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 621606691.

It is not a weakly prime, because it can be changed into another prime (621606191) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 310803345 + 310803346.

It is an arithmetic number, because the mean of its divisors is an integer number (310803346).

Almost surely, 2^621606691 is an apocalyptic number.

621606691 is a deficient number, since it is larger than the sum of its proper divisors (1).

621606691 is an equidigital number, since it uses as much as digits as its factorization.

621606691 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 23328, while the sum is 37.

The square root of 621606691 is about 24932.0414527170. The cubic root of 621606691 is about 853.4378374244.

The spelling of 621606691 in words is "six hundred twenty-one million, six hundred six thousand, six hundred ninety-one".