650236721 has 2 divisors, whose sum is σ = 650236722. Its totient is φ = 650236720.

The previous prime is 650236649. The next prime is 650236739. The reversal of 650236721 is 127632056.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 649689121 + 547600 = 25489^2 + 740^2 .

It is a cyclic number.

It is not a de Polignac number, because 650236721 - 2¹⁰ = 650235697 is a prime.

It is a super-4 number, since 4×650236721⁴ (a number of 36 digits) contains 4444 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (650236751) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 325118360 + 325118361.

It is an arithmetic number, because the mean of its divisors is an integer number (325118361).

Almost surely, 2^650236721 is an apocalyptic number.

It is an amenable number.

650236721 is a deficient number, since it is larger than the sum of its proper divisors (1).

650236721 is an equidigital number, since it uses as much as digits as its factorization.

650236721 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 15120, while the sum is 32.

The square root of 650236721 is about 25499.7396261217. The cubic root of 650236721 is about 866.3442500072.

Adding to 650236721 its reverse (127632056), we get a palindrome (777868777).

The spelling of 650236721 in words is "six hundred fifty million, two hundred thirty-six thousand, seven hundred twenty-one".