643542727245349 has 2 divisors, whose sum is σ = 643542727245350. Its totient is φ = 643542727245348.

The previous prime is 643542727245337. The next prime is 643542727245413. The reversal of 643542727245349 is 943542727245346.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 588166537101025 + 55376190144324 = 24252145^2 + 7441518^2 .

It is a cyclic number.

It is not a de Polignac number, because 643542727245349 - 2³¹ = 643540579761701 is a prime.

It is a super-2 number, since 2×643542727245349² (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 (643542727245149) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321771363622674 + 321771363622675.

It is an arithmetic number, because the mean of its divisors is an integer number (321771363622675).

Almost surely, 2^{643542727245349} is an apocalyptic number.

It is an amenable number.

643542727245349 is a deficient number, since it is larger than the sum of its proper divisors (1).

643542727245349 is an equidigital number, since it uses as much as digits as its factorization.

643542727245349 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1219276800, while the sum is 67.

The spelling of 643542727245349 in words is "six hundred forty-three trillion, five hundred forty-two billion, seven hundred twenty-seven million, two hundred forty-five thousand, three hundred forty-nine".