643847126077 has 2 divisors, whose sum is σ = 643847126078. Its totient is φ = 643847126076.

The previous prime is 643847126057. The next prime is 643847126149. The reversal of 643847126077 is 770621748346.

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., 614790855396 + 29056270681 = 784086^2 + 170459^2 .

It is a cyclic number.

It is not a de Polignac number, because 643847126077 - 2⁷ = 643847125949 is a prime.

It is a super-2 number, since 2×643847126077² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (643847126057) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321923563038 + 321923563039.

It is an arithmetic number, because the mean of its divisors is an integer number (321923563039).

Almost surely, 2^643847126077 is an apocalyptic number.

It is an amenable number.

643847126077 is a deficient number, since it is larger than the sum of its proper divisors (1).

643847126077 is an equidigital number, since it uses as much as digits as its factorization.

643847126077 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 9483264, while the sum is 55.

The spelling of 643847126077 in words is "six hundred forty-three billion, eight hundred forty-seven million, one hundred twenty-six thousand, seventy-seven".