664772447 has 2 divisors, whose sum is σ = 664772448. Its totient is φ = 664772446.

The previous prime is 664772441. The next prime is 664772461. The reversal of 664772447 is 744277466.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 664772447 - 2⁴ = 664772431 is a prime.

It is a super-3 number, since 3×664772447³ (a number of 27 digits) contains 333 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (664772441) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332386223 + 332386224.

It is an arithmetic number, because the mean of its divisors is an integer number (332386224).

Almost surely, 2^664772447 is an apocalyptic number.

664772447 is a deficient number, since it is larger than the sum of its proper divisors (1).

664772447 is an equidigital number, since it uses as much as digits as its factorization.

664772447 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1580544, while the sum is 47.

The square root of 664772447 is about 25783.1814755278. The cubic root of 664772447 is about 872.7523032321.

The spelling of 664772447 in words is "six hundred sixty-four million, seven hundred seventy-two thousand, four hundred forty-seven".