664726297 has 2 divisors, whose sum is σ = 664726298. Its totient is φ = 664726296.

The previous prime is 664726291. The next prime is 664726331. The reversal of 664726297 is 792627466.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 642926736 + 21799561 = 25356^2 + 4669^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-664726297 is a prime.

It is a super-2 number, since 2×664726297² = 883722099846664418, 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 664726297.

It is not a weakly prime, because it can be changed into another prime (664726291) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332363148 + 332363149.

It is an arithmetic number, because the mean of its divisors is an integer number (332363149).

Almost surely, 2^664726297 is an apocalyptic number.

It is an amenable number.

664726297 is a deficient number, since it is larger than the sum of its proper divisors (1).

664726297 is an equidigital number, since it uses as much as digits as its factorization.

664726297 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1524096, while the sum is 49.

The square root of 664726297 is about 25782.2864967404. The cubic root of 664726297 is about 872.7321066214.

The spelling of 664726297 in words is "six hundred sixty-four million, seven hundred twenty-six thousand, two hundred ninety-seven".