421363555661 has 2 divisors, whose sum is σ = 421363555662. Its totient is φ = 421363555660.

The previous prime is 421363555643. The next prime is 421363555703. The reversal of 421363555661 is 166555363124.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 396736216900 + 24627338761 = 629870^2 + 156931^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-421363555661 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (421363555601) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 210681777830 + 210681777831.

It is an arithmetic number, because the mean of its divisors is an integer number (210681777831).

Almost surely, 2^421363555661 is an apocalyptic number.

It is an amenable number.

421363555661 is a deficient number, since it is larger than the sum of its proper divisors (1).

421363555661 is an equidigital number, since it uses as much as digits as its factorization.

421363555661 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1944000, while the sum is 47.

The spelling of 421363555661 in words is "four hundred twenty-one billion, three hundred sixty-three million, five hundred fifty-five thousand, six hundred sixty-one".