643019215977401 has 2 divisors, whose sum is σ = 643019215977402. Its totient is φ = 643019215977400.

The previous prime is 643019215977389. The next prime is 643019215977433. The reversal of 643019215977401 is 104779512910346.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 497747299683001 + 145271916294400 = 22310251^2 + 12052880^2 .

It is a cyclic number.

It is not a de Polignac number, because 643019215977401 - 2³⁰ = 643018142235577 is a prime.

It is not a weakly prime, because it can be changed into another prime (643019215977601) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321509607988700 + 321509607988701.

It is an arithmetic number, because the mean of its divisors is an integer number (321509607988701).

Almost surely, 2^{643019215977401} is an apocalyptic number.

It is an amenable number.

643019215977401 is a deficient number, since it is larger than the sum of its proper divisors (1).

643019215977401 is an equidigital number, since it uses as much as digits as its factorization.

643019215977401 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 11430720, while the sum is 59.

The spelling of 643019215977401 in words is "six hundred forty-three trillion, nineteen billion, two hundred fifteen million, nine hundred seventy-seven thousand, four hundred one".