664423129 has 2 divisors, whose sum is σ = 664423130. Its totient is φ = 664423128.

The previous prime is 664423117. The next prime is 664423139. The reversal of 664423129 is 921324466.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 553331529 + 111091600 = 23523^2 + 10540^2 .

It is a cyclic number.

It is not a de Polignac number, because 664423129 - 2¹⁵ = 664390361 is a prime.

It is not a weakly prime, because it can be changed into another prime (664423139) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332211564 + 332211565.

It is an arithmetic number, because the mean of its divisors is an integer number (332211565).

Almost surely, 2^664423129 is an apocalyptic number.

It is an amenable number.

664423129 is a deficient number, since it is larger than the sum of its proper divisors (1).

664423129 is an equidigital number, since it uses as much as digits as its factorization.

664423129 is an evil number, because the sum of its binary digits is even.

The product of its digits is 62208, while the sum is 37.

The square root of 664423129 is about 25776.4064407745. The cubic root of 664423129 is about 872.5994080543.

The spelling of 664423129 in words is "six hundred sixty-four million, four hundred twenty-three thousand, one hundred twenty-nine".