421636643717 has 2 divisors, whose sum is σ = 421636643718. Its totient is φ = 421636643716.

The previous prime is 421636643683. The next prime is 421636643761. The reversal of 421636643717 is 717346636124.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 266716470916 + 154920172801 = 516446^2 + 393599^2 .

It is a cyclic number.

It is not a de Polignac number, because 421636643717 - 2³² = 417341676421 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (421636643917) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 210818321858 + 210818321859.

It is an arithmetic number, because the mean of its divisors is an integer number (210818321859).

Almost surely, 2^421636643717 is an apocalyptic number.

It is an amenable number.

421636643717 is a deficient number, since it is larger than the sum of its proper divisors (1).

421636643717 is an equidigital number, since it uses as much as digits as its factorization.

421636643717 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3048192, while the sum is 50.

The spelling of 421636643717 in words is "four hundred twenty-one billion, six hundred thirty-six million, six hundred forty-three thousand, seven hundred seventeen".