649405993 has 2 divisors, whose sum is σ = 649405994. Its totient is φ = 649405992.

The previous prime is 649405987. The next prime is 649406041. The reversal of 649405993 is 399504946.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 356756544 + 292649449 = 18888^2 + 17107^2 .

It is a cyclic number.

It is not a de Polignac number, because 649405993 - 2⁹ = 649405481 is a prime.

It is not a weakly prime, because it can be changed into another prime (649405193) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 324702996 + 324702997.

It is an arithmetic number, because the mean of its divisors is an integer number (324702997).

Almost surely, 2^649405993 is an apocalyptic number.

It is an amenable number.

649405993 is a deficient number, since it is larger than the sum of its proper divisors (1).

649405993 is an equidigital number, since it uses as much as digits as its factorization.

649405993 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1049760, while the sum is 49.

The square root of 649405993 is about 25483.4454695593. The cubic root of 649405993 is about 865.9751520516.

The spelling of 649405993 in words is "six hundred forty-nine million, four hundred five thousand, nine hundred ninety-three".