420766721 has 2 divisors, whose sum is σ = 420766722. Its totient is φ = 420766720.

The previous prime is 420766691. The next prime is 420766727. The reversal of 420766721 is 127667024.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 257923600 + 162843121 = 16060^2 + 12761^2 .

It is a cyclic number.

It is not a de Polignac number, because 420766721 - 2⁶ = 420766657 is a prime.

It is not a weakly prime, because it can be changed into another prime (420766727) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 210383360 + 210383361.

It is an arithmetic number, because the mean of its divisors is an integer number (210383361).

Almost surely, 2^420766721 is an apocalyptic number.

It is an amenable number.

420766721 is a deficient number, since it is larger than the sum of its proper divisors (1).

420766721 is an equidigital number, since it uses as much as digits as its factorization.

420766721 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 28224, while the sum is 35.

The square root of 420766721 is about 20512.5990795901. The cubic root of 420766721 is about 749.3426661253.

The spelling of 420766721 in words is "four hundred twenty million, seven hundred sixty-six thousand, seven hundred twenty-one".