664624549 has 2 divisors, whose sum is σ = 664624550. Its totient is φ = 664624548.

The previous prime is 664624507. The next prime is 664624559. The reversal of 664624549 is 945426466.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 427248900 + 237375649 = 20670^2 + 15407^2 .

It is a cyclic number.

It is not a de Polignac number, because 664624549 - 2⁷ = 664624421 is a prime.

It is a super-2 number, since 2×664624549² = 883451582266906802, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 664624499 and 664624508.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (664624559) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332312274 + 332312275.

It is an arithmetic number, because the mean of its divisors is an integer number (332312275).

Almost surely, 2^664624549 is an apocalyptic number.

It is an amenable number.

664624549 is a deficient number, since it is larger than the sum of its proper divisors (1).

664624549 is an equidigital number, since it uses as much as digits as its factorization.

664624549 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1244160, while the sum is 46.

The square root of 664624549 is about 25780.3132060105. The cubic root of 664624549 is about 872.6875753720.

The spelling of 664624549 in words is "six hundred sixty-four million, six hundred twenty-four thousand, five hundred forty-nine".