643716020933 has 2 divisors, whose sum is σ = 643716020934. Its totient is φ = 643716020932.

The previous prime is 643716020929. The next prime is 643716020971. The reversal of 643716020933 is 339020617346.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 551325555169 + 92390465764 = 742513^2 + 303958^2 .

It is a cyclic number.

It is not a de Polignac number, because 643716020933 - 2² = 643716020929 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (643716050933) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321858010466 + 321858010467.

It is an arithmetic number, because the mean of its divisors is an integer number (321858010467).

Almost surely, 2^643716020933 is an apocalyptic number.

It is an amenable number.

643716020933 is a deficient number, since it is larger than the sum of its proper divisors (1).

643716020933 is an equidigital number, since it uses as much as digits as its factorization.

643716020933 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 489888, while the sum is 44.

The spelling of 643716020933 in words is "six hundred forty-three billion, seven hundred sixteen million, twenty thousand, nine hundred thirty-three".