421989433 has 2 divisors, whose sum is σ = 421989434. Its totient is φ = 421989432.

The previous prime is 421989427. The next prime is 421989437. The reversal of 421989433 is 334989124.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 421563024 + 426409 = 20532^2 + 653^2 .

It is a cyclic number.

It is not a de Polignac number, because 421989433 - 2²⁵ = 388435001 is a prime.

It is a super-2 number, since 2×421989433² = 356150163127322978, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 421989433.

It is not a weakly prime, because it can be changed into another prime (421989437) 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, 210994716 + 210994717.

It is an arithmetic number, because the mean of its divisors is an integer number (210994717).

Almost surely, 2^421989433 is an apocalyptic number.

It is an amenable number.

421989433 is a deficient number, since it is larger than the sum of its proper divisors (1).

421989433 is an equidigital number, since it uses as much as digits as its factorization.

421989433 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 186624, while the sum is 43.

The square root of 421989433 is about 20542.3813858082. The cubic root of 421989433 is about 750.0678060178.

The spelling of 421989433 in words is "four hundred twenty-one million, nine hundred eighty-nine thousand, four hundred thirty-three".