421691773 has 2 divisors, whose sum is σ = 421691774. Its totient is φ = 421691772.

The previous prime is 421691747. The next prime is 421691779. The reversal of 421691773 is 377196124.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 242051364 + 179640409 = 15558^2 + 13403^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-421691773 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (421691779) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 210845886 + 210845887.

It is an arithmetic number, because the mean of its divisors is an integer number (210845887).

Almost surely, 2^421691773 is an apocalyptic number.

It is an amenable number.

421691773 is a deficient number, since it is larger than the sum of its proper divisors (1).

421691773 is an equidigital number, since it uses as much as digits as its factorization.

421691773 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 63504, while the sum is 40.

The square root of 421691773 is about 20535.1350859935. The cubic root of 421691773 is about 749.8914053141.

The spelling of 421691773 in words is "four hundred twenty-one million, six hundred ninety-one thousand, seven hundred seventy-three".