402655655621 has 2 divisors, whose sum is σ = 402655655622. Its totient is φ = 402655655620.

The previous prime is 402655655603. The next prime is 402655655653. The reversal of 402655655621 is 126556556204.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 376641191521 + 26014464100 = 613711^2 + 161290^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-402655655621 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (402655655671) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 201327827810 + 201327827811.

It is an arithmetic number, because the mean of its divisors is an integer number (201327827811).

Almost surely, 2^402655655621 is an apocalyptic number.

It is an amenable number.

402655655621 is a deficient number, since it is larger than the sum of its proper divisors (1).

402655655621 is an equidigital number, since it uses as much as digits as its factorization.

402655655621 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2160000, while the sum is 47.

The spelling of 402655655621 in words is "four hundred two billion, six hundred fifty-five million, six hundred fifty-five thousand, six hundred twenty-one".