643156531279 has 2 divisors, whose sum is σ = 643156531280. Its totient is φ = 643156531278.

The previous prime is 643156531253. The next prime is 643156531291. The reversal of 643156531279 is 972135651346.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 643156531279 - 2⁹ = 643156530767 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (643156531229) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321578265639 + 321578265640.

It is an arithmetic number, because the mean of its divisors is an integer number (321578265640).

Almost surely, 2^643156531279 is an apocalyptic number.

643156531279 is a deficient number, since it is larger than the sum of its proper divisors (1).

643156531279 is an equidigital number, since it uses as much as digits as its factorization.

643156531279 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4082400, while the sum is 52.

The spelling of 643156531279 in words is "six hundred forty-three billion, one hundred fifty-six million, five hundred thirty-one thousand, two hundred seventy-nine".