650736721 has 2 divisors, whose sum is σ = 650736722. Its totient is φ = 650736720.

The previous prime is 650736689. The next prime is 650736739. The reversal of 650736721 is 127637056.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 445674321 + 205062400 = 21111^2 + 14320^2 .

It is a cyclic number.

It is not a de Polignac number, because 650736721 - 2⁵ = 650736689 is a prime.

It is not a weakly prime, because it can be changed into another prime (650736781) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 325368360 + 325368361.

It is an arithmetic number, because the mean of its divisors is an integer number (325368361).

Almost surely, 2^650736721 is an apocalyptic number.

It is an amenable number.

650736721 is a deficient number, since it is larger than the sum of its proper divisors (1).

650736721 is an equidigital number, since it uses as much as digits as its factorization.

650736721 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 52920, while the sum is 37.

The square root of 650736721 is about 25509.5417638185. The cubic root of 650736721 is about 866.5662517947.

The spelling of 650736721 in words is "six hundred fifty million, seven hundred thirty-six thousand, seven hundred twenty-one".