643326623377 has 2 divisors, whose sum is σ = 643326623378. Its totient is φ = 643326623376.

The previous prime is 643326623339. The next prime is 643326623389. The reversal of 643326623377 is 773326623346.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 633041418321 + 10285205056 = 795639^2 + 101416^2 .

It is a cyclic number.

It is not a de Polignac number, because 643326623377 - 2¹⁵ = 643326590609 is a prime.

It is not a weakly prime, because it can be changed into another prime (643326623977) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321663311688 + 321663311689.

It is an arithmetic number, because the mean of its divisors is an integer number (321663311689).

Almost surely, 2^643326623377 is an apocalyptic number.

It is an amenable number.

643326623377 is a deficient number, since it is larger than the sum of its proper divisors (1).

643326623377 is an equidigital number, since it uses as much as digits as its factorization.

643326623377 is an evil number, because the sum of its binary digits is even.

The product of its digits is 13716864, while the sum is 52.

The spelling of 643326623377 in words is "six hundred forty-three billion, three hundred twenty-six million, six hundred twenty-three thousand, three hundred seventy-seven".