650738021 has 2 divisors, whose sum is σ = 650738022. Its totient is φ = 650738020.

The previous prime is 650738017. The next prime is 650738111. The reversal of 650738021 is 120837056.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 478996996 + 171741025 = 21886^2 + 13105^2 .

It is a cyclic number.

It is not a de Polignac number, because 650738021 - 2² = 650738017 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (650738321) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 325369010 + 325369011.

It is an arithmetic number, because the mean of its divisors is an integer number (325369011).

Almost surely, 2^650738021 is an apocalyptic number.

It is an amenable number.

650738021 is a deficient number, since it is larger than the sum of its proper divisors (1).

650738021 is an equidigital number, since it uses as much as digits as its factorization.

650738021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 10080, while the sum is 32.

The square root of 650738021 is about 25509.5672444673. The cubic root of 650738021 is about 866.5668288511.

The spelling of 650738021 in words is "six hundred fifty million, seven hundred thirty-eight thousand, twenty-one".