649923917 has 2 divisors, whose sum is σ = 649923918. Its totient is φ = 649923916.

The previous prime is 649923893. The next prime is 649923929. The reversal of 649923917 is 719329946.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 626701156 + 23222761 = 25034^2 + 4819^2 .

It is a cyclic number.

It is not a de Polignac number, because 649923917 - 2¹² = 649919821 is a prime.

It is a Chen prime.

It is equal to p_33789668 and since 649923917 and 33789668 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (649923997) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 324961958 + 324961959.

It is an arithmetic number, because the mean of its divisors is an integer number (324961959).

Almost surely, 2^649923917 is an apocalyptic number.

It is an amenable number.

649923917 is a deficient number, since it is larger than the sum of its proper divisors (1).

649923917 is an equidigital number, since it uses as much as digits as its factorization.

649923917 is an evil number, because the sum of its binary digits is even.

The product of its digits is 734832, while the sum is 50.

The square root of 649923917 is about 25493.6054139072. The cubic root of 649923917 is about 866.2053060376.

The spelling of 649923917 in words is "six hundred forty-nine million, nine hundred twenty-three thousand, nine hundred seventeen".