421643504641 has 2 divisors, whose sum is σ = 421643504642. Its totient is φ = 421643504640.

The previous prime is 421643504629. The next prime is 421643504651. The reversal of 421643504641 is 146405346124.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 401480640625 + 20162864016 = 633625^2 + 141996^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-421643504641 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 421643504594 and 421643504603.

It is not a weakly prime, because it can be changed into another prime (421643504651) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 210821752320 + 210821752321.

It is an arithmetic number, because the mean of its divisors is an integer number (210821752321).

Almost surely, 2^421643504641 is an apocalyptic number.

It is an amenable number.

421643504641 is a deficient number, since it is larger than the sum of its proper divisors (1).

421643504641 is an equidigital number, since it uses as much as digits as its factorization.

421643504641 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 276480, while the sum is 40.

The spelling of 421643504641 in words is "four hundred twenty-one billion, six hundred forty-three million, five hundred four thousand, six hundred forty-one".