6431650616561 has 2 divisors, whose sum is σ = 6431650616562. Its totient is φ = 6431650616560.

The previous prime is 6431650616557. The next prime is 6431650616597. The reversal of 6431650616561 is 1656160561346.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 6337428630625 + 94221985936 = 2517425^2 + 306956^2 .

It is a cyclic number.

It is not a de Polignac number, because 6431650616561 - 2² = 6431650616557 is a prime.

It is a super-2 number, since 2×6431650616561² (a number of 26 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (6431650816561) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3215825308280 + 3215825308281.

It is an arithmetic number, because the mean of its divisors is an integer number (3215825308281).

Almost surely, 2^{6431650616561} is an apocalyptic number.

It is an amenable number.

6431650616561 is a deficient number, since it is larger than the sum of its proper divisors (1).

6431650616561 is an equidigital number, since it uses as much as digits as its factorization.

6431650616561 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2332800, while the sum is 50.

The spelling of 6431650616561 in words is "six trillion, four hundred thirty-one billion, six hundred fifty million, six hundred sixteen thousand, five hundred sixty-one".