664021429 has 2 divisors, whose sum is σ = 664021430. Its totient is φ = 664021428.

The previous prime is 664021403. The next prime is 664021441. The reversal of 664021429 is 924120466.

664021429 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 633881329 + 30140100 = 25177^2 + 5490^2 .

It is a cyclic number.

It is not a de Polignac number, because 664021429 - 2⁷ = 664021301 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 664021394 and 664021403.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (664021489) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332010714 + 332010715.

It is an arithmetic number, because the mean of its divisors is an integer number (332010715).

Almost surely, 2^664021429 is an apocalyptic number.

It is an amenable number.

664021429 is a deficient number, since it is larger than the sum of its proper divisors (1).

664021429 is an equidigital number, since it uses as much as digits as its factorization.

664021429 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 20736, while the sum is 34.

The square root of 664021429 is about 25768.6132533359. The cubic root of 664021429 is about 872.4235192113.

The spelling of 664021429 in words is "six hundred sixty-four million, twenty-one thousand, four hundred twenty-nine".