643532651497 has 2 divisors, whose sum is σ = 643532651498. Its totient is φ = 643532651496.

The previous prime is 643532651491. The next prime is 643532651609. The reversal of 643532651497 is 794156235346.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 536862478681 + 106670172816 = 732709^2 + 326604^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-643532651497 is a prime.

It is not a weakly prime, because it can be changed into another prime (643532651491) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321766325748 + 321766325749.

It is an arithmetic number, because the mean of its divisors is an integer number (321766325749).

Almost surely, 2^643532651497 is an apocalyptic number.

It is an amenable number.

643532651497 is a deficient number, since it is larger than the sum of its proper divisors (1).

643532651497 is an equidigital number, since it uses as much as digits as its factorization.

643532651497 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 16329600, while the sum is 55.

It can be divided in two parts, 643532 and 651497, that added together give a cube (1295029 = 109³).

The spelling of 643532651497 in words is "six hundred forty-three billion, five hundred thirty-two million, six hundred fifty-one thousand, four hundred ninety-seven".