420684521 has 2 divisors, whose sum is σ = 420684522. Its totient is φ = 420684520.

The previous prime is 420684497. The next prime is 420684541. The reversal of 420684521 is 125486024.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 250747225 + 169937296 = 15835^2 + 13036^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-420684521 is a prime.

It is not a weakly prime, because it can be changed into another prime (420684541) 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, 210342260 + 210342261.

It is an arithmetic number, because the mean of its divisors is an integer number (210342261).

Almost surely, 2^420684521 is an apocalyptic number.

It is an amenable number.

420684521 is a deficient number, since it is larger than the sum of its proper divisors (1).

420684521 is an equidigital number, since it uses as much as digits as its factorization.

420684521 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 15360, while the sum is 32.

The square root of 420684521 is about 20510.5953350945. The cubic root of 420684521 is about 749.2938663386.

The spelling of 420684521 in words is "four hundred twenty million, six hundred eighty-four thousand, five hundred twenty-one".