420654821 has 2 divisors, whose sum is σ = 420654822. Its totient is φ = 420654820.

The previous prime is 420654803. The next prime is 420654847. The reversal of 420654821 is 128456024.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 250873921 + 169780900 = 15839^2 + 13030^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-420654821 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (420654881) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 210327410 + 210327411.

It is an arithmetic number, because the mean of its divisors is an integer number (210327411).

Almost surely, 2^420654821 is an apocalyptic number.

It is an amenable number.

420654821 is a deficient number, since it is larger than the sum of its proper divisors (1).

420654821 is an equidigital number, since it uses as much as digits as its factorization.

420654821 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 420654821 is about 20509.8713062759. The cubic root of 420654821 is about 749.2762327356.

The spelling of 420654821 in words is "four hundred twenty million, six hundred fifty-four thousand, eight hundred twenty-one".