651661063252321 has 2 divisors, whose sum is σ = 651661063252322. Its totient is φ = 651661063252320.

The previous prime is 651661063252273. The next prime is 651661063252349. The reversal of 651661063252321 is 123252360166156.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 399282881700096 + 252378181552225 = 19982064^2 + 15886415^2 .

It is a cyclic number.

It is not a de Polignac number, because 651661063252321 - 2¹⁷ = 651661063121249 is a prime.

It is a super-2 number, since 2×651661063252321² (a number of 30 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (651661063252391) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 325830531626160 + 325830531626161.

It is an arithmetic number, because the mean of its divisors is an integer number (325830531626161).

Almost surely, 2^{651661063252321} is an apocalyptic number.

It is an amenable number.

651661063252321 is a deficient number, since it is larger than the sum of its proper divisors (1).

651661063252321 is an equidigital number, since it uses as much as digits as its factorization.

651661063252321 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2332800, while the sum is 49.

The spelling of 651661063252321 in words is "six hundred fifty-one trillion, six hundred sixty-one billion, sixty-three million, two hundred fifty-two thousand, three hundred twenty-one".