626610661 has 2 divisors, whose sum is σ = 626610662. Its totient is φ = 626610660.

The previous prime is 626610659. The next prime is 626610683. The reversal of 626610661 is 166016626.

626610661 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 480442561 + 146168100 = 21919^2 + 12090^2 .

It is a cyclic number.

It is not a de Polignac number, because 626610661 - 2¹ = 626610659 is a prime.

Together with 626610659, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (626610961) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 313305330 + 313305331.

It is an arithmetic number, because the mean of its divisors is an integer number (313305331).

Almost surely, 2^626610661 is an apocalyptic number.

It is an amenable number.

626610661 is a deficient number, since it is larger than the sum of its proper divisors (1).

626610661 is an equidigital number, since it uses as much as digits as its factorization.

626610661 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 15552, while the sum is 34.

The square root of 626610661 is about 25032.1924928681. The cubic root of 626610661 is about 855.7217944174.

The spelling of 626610661 in words is "six hundred twenty-six million, six hundred ten thousand, six hundred sixty-one".