421001389 has 2 divisors, whose sum is σ = 421001390. Its totient is φ = 421001388.

The previous prime is 421001369. The next prime is 421001423. The reversal of 421001389 is 983100124.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 351562500 + 69438889 = 18750^2 + 8333^2 .

It is a cyclic number.

It is not a de Polignac number, because 421001389 - 2¹⁵ = 420968621 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 (421001369) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 210500694 + 210500695.

It is an arithmetic number, because the mean of its divisors is an integer number (210500695).

Almost surely, 2^421001389 is an apocalyptic number.

It is an amenable number.

421001389 is a deficient number, since it is larger than the sum of its proper divisors (1).

421001389 is an equidigital number, since it uses as much as digits as its factorization.

421001389 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1728, while the sum is 28.

The square root of 421001389 is about 20518.3183765142. The cubic root of 421001389 is about 749.4819468362.

The spelling of 421001389 in words is "four hundred twenty-one million, one thousand, three hundred eighty-nine".