643019215977349 has 2 divisors, whose sum is σ = 643019215977350. Its totient is φ = 643019215977348.

The previous prime is 643019215977323. The next prime is 643019215977389. The reversal of 643019215977349 is 943779512910346.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 368327375108449 + 274691840868900 = 19191857^2 + 16573830^2 .

It is a cyclic number.

It is not a de Polignac number, because 643019215977349 - 2³⁷ = 642881777023877 is a prime.

It is a super-2 number, since 2×643019215977349² (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 (643019215977389) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321509607988674 + 321509607988675.

It is an arithmetic number, because the mean of its divisors is an integer number (321509607988675).

Almost surely, 2^{643019215977349} is an apocalyptic number.

It is an amenable number.

643019215977349 is a deficient number, since it is larger than the sum of its proper divisors (1).

643019215977349 is an equidigital number, since it uses as much as digits as its factorization.

643019215977349 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 308629440, while the sum is 70.

The spelling of 643019215977349 in words is "six hundred forty-three trillion, nineteen billion, two hundred fifteen million, nine hundred seventy-seven thousand, three hundred forty-nine".