664160729 has 2 divisors, whose sum is σ = 664160730. Its totient is φ = 664160728.

The previous prime is 664160659. The next prime is 664160747. The reversal of 664160729 is 927061466.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 652904704 + 11256025 = 25552^2 + 3355^2 .

It is a cyclic number.

It is not a de Polignac number, because 664160729 - 2²⁸ = 395725273 is a prime.

It is a super-2 number, since 2×664160729² = 882218947891622882, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (664120729) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332080364 + 332080365.

It is an arithmetic number, because the mean of its divisors is an integer number (332080365).

Almost surely, 2^664160729 is an apocalyptic number.

It is an amenable number.

664160729 is a deficient number, since it is larger than the sum of its proper divisors (1).

664160729 is an equidigital number, since it uses as much as digits as its factorization.

664160729 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 108864, while the sum is 41.

The square root of 664160729 is about 25771.3160121869. The cubic root of 664160729 is about 872.4845213084.

The spelling of 664160729 in words is "six hundred sixty-four million, one hundred sixty thousand, seven hundred twenty-nine".