1669243421 has 2 divisors, whose sum is σ = 1669243422. Its totient is φ = 1669243420.

The previous prime is 1669243417. The next prime is 1669243501. The reversal of 1669243421 is 1243429661.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1658932900 + 10310521 = 40730^2 + 3211^2 .

It is a cyclic number.

It is not a de Polignac number, because 1669243421 - 2² = 1669243417 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1669243021) 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, 834621710 + 834621711.

It is an arithmetic number, because the mean of its divisors is an integer number (834621711).

Almost surely, 2^1669243421 is an apocalyptic number.

It is an amenable number.

1669243421 is a deficient number, since it is larger than the sum of its proper divisors (1).

1669243421 is an equidigital number, since it uses as much as digits as its factorization.

1669243421 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 62208, while the sum is 38.

The square root of 1669243421 is about 40856.3755245127. The cubic root of 1669243421 is about 1186.2418028949.

The spelling of 1669243421 in words is "one billion, six hundred sixty-nine million, two hundred forty-three thousand, four hundred twenty-one".