420389993 has 2 divisors, whose sum is σ = 420389994. Its totient is φ = 420389992.

The previous prime is 420389989. The next prime is 420390013. The reversal of 420389993 is 399983024.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 334048729 + 86341264 = 18277^2 + 9292^2 .

It is a cyclic number.

It is not a de Polignac number, because 420389993 - 2² = 420389989 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (420389903) 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, 210194996 + 210194997.

It is an arithmetic number, because the mean of its divisors is an integer number (210194997).

Almost surely, 2^420389993 is an apocalyptic number.

It is an amenable number.

420389993 is a deficient number, since it is larger than the sum of its proper divisors (1).

420389993 is an equidigital number, since it uses as much as digits as its factorization.

420389993 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 419904, while the sum is 47.

The square root of 420389993 is about 20503.4141791069. The cubic root of 420389993 is about 749.1189612848.

The spelling of 420389993 in words is "four hundred twenty million, three hundred eighty-nine thousand, nine hundred ninety-three".