420221093987581 has 2 divisors, whose sum is σ = 420221093987582. Its totient is φ = 420221093987580.

The previous prime is 420221093987477. The next prime is 420221093987599. The reversal of 420221093987581 is 185789390122024.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 303151939965081 + 117069154022500 = 17411259^2 + 10819850^2 .

It is a cyclic number.

It is not a de Polignac number, because 420221093987581 - 2²⁹ = 420220557116669 is a prime.

It is a super-2 number, since 2×420221093987581² (a number of 30 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (420221094987581) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 210110546993790 + 210110546993791.

It is an arithmetic number, because the mean of its divisors is an integer number (210110546993791).

Almost surely, 2^{420221093987581} is an apocalyptic number.

It is an amenable number.

420221093987581 is a deficient number, since it is larger than the sum of its proper divisors (1).

420221093987581 is an equidigital number, since it uses as much as digits as its factorization.

420221093987581 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 17418240, while the sum is 61.

The spelling of 420221093987581 in words is "four hundred twenty trillion, two hundred twenty-one billion, ninety-three million, nine hundred eighty-seven thousand, five hundred eighty-one".