643624026654181 has 2 divisors, whose sum is σ = 643624026654182. Its totient is φ = 643624026654180.

The previous prime is 643624026654043. The next prime is 643624026654253. The reversal of 643624026654181 is 181456620426346.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 553931951706081 + 89692074948100 = 23535759^2 + 9470590^2 .

It is a cyclic number.

It is not a de Polignac number, because 643624026654181 - 2²¹ = 643624024557029 is a prime.

It is a super-2 number, since 2×643624026654181² (a number of 30 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (643624056654181) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321812013327090 + 321812013327091.

It is an arithmetic number, because the mean of its divisors is an integer number (321812013327091).

Almost surely, 2^{643624026654181} is an apocalyptic number.

It is an amenable number.

643624026654181 is a deficient number, since it is larger than the sum of its proper divisors (1).

643624026654181 is an equidigital number, since it uses as much as digits as its factorization.

643624026654181 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 39813120, while the sum is 58.

The spelling of 643624026654181 in words is "six hundred forty-three trillion, six hundred twenty-four billion, twenty-six million, six hundred fifty-four thousand, one hundred eighty-one".