643115121401 has 2 divisors, whose sum is σ = 643115121402. Its totient is φ = 643115121400.

The previous prime is 643115121371. The next prime is 643115121409. The reversal of 643115121401 is 104121511346.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 504879881401 + 138235240000 = 710549^2 + 371800^2 .

It is a cyclic number.

It is not a de Polignac number, because 643115121401 - 2¹⁰ = 643115120377 is a prime.

It is not a weakly prime, because it can be changed into another prime (643115121409) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321557560700 + 321557560701.

It is an arithmetic number, because the mean of its divisors is an integer number (321557560701).

Almost surely, 2^643115121401 is an apocalyptic number.

It is an amenable number.

643115121401 is a deficient number, since it is larger than the sum of its proper divisors (1).

643115121401 is an equidigital number, since it uses as much as digits as its factorization.

643115121401 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2880, while the sum is 29.

Adding to 643115121401 its reverse (104121511346), we get a palindrome (747236632747).

The spelling of 643115121401 in words is "six hundred forty-three billion, one hundred fifteen million, one hundred twenty-one thousand, four hundred one".