420640573 has 2 divisors, whose sum is σ = 420640574. Its totient is φ = 420640572.

The previous prime is 420640543. The next prime is 420640589. The reversal of 420640573 is 375046024.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 417262329 + 3378244 = 20427^2 + 1838^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-420640573 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (420640543) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 210320286 + 210320287.

It is an arithmetic number, because the mean of its divisors is an integer number (210320287).

Almost surely, 2^420640573 is an apocalyptic number.

It is an amenable number.

420640573 is a deficient number, since it is larger than the sum of its proper divisors (1).

420640573 is an equidigital number, since it uses as much as digits as its factorization.

420640573 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 20160, while the sum is 31.

The square root of 420640573 is about 20509.5239583955. The cubic root of 420640573 is about 749.2677730613.

Adding to 420640573 its reverse (375046024), we get a palindrome (795686597).

The spelling of 420640573 in words is "four hundred twenty million, six hundred forty thousand, five hundred seventy-three".