649538557 has 2 divisors, whose sum is σ = 649538558. Its totient is φ = 649538556.

The previous prime is 649538467. The next prime is 649538581. The reversal of 649538557 is 755835946.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 571640281 + 77898276 = 23909^2 + 8826^2 .

It is a cyclic number.

It is not a de Polignac number, because 649538557 - 2¹¹ = 649536509 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (649538657) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 324769278 + 324769279.

It is an arithmetic number, because the mean of its divisors is an integer number (324769279).

Almost surely, 2^649538557 is an apocalyptic number.

It is an amenable number.

649538557 is a deficient number, since it is larger than the sum of its proper divisors (1).

649538557 is an equidigital number, since it uses as much as digits as its factorization.

649538557 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4536000, while the sum is 52.

The square root of 649538557 is about 25486.0463195059. The cubic root of 649538557 is about 866.0340722140.

The spelling of 649538557 in words is "six hundred forty-nine million, five hundred thirty-eight thousand, five hundred fifty-seven".