643610042241 has 4 divisors (see below), whose sum is σ = 858146722992. Its totient is φ = 429073361492.

The previous prime is 643610042237. The next prime is 643610042281. The reversal of 643610042241 is 142240016346.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 643610042241 - 2² = 643610042237 is a prime.

It is not an unprimeable number, because it can be changed into a prime (643610042281) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 107268340371 + ... + 107268340376.

It is an arithmetic number, because the mean of its divisors is an integer number (214536680748).

Almost surely, 2^643610042241 is an apocalyptic number.

It is an amenable number.

643610042241 is a deficient number, since it is larger than the sum of its proper divisors (214536680751).

643610042241 is a wasteful number, since it uses less digits than its factorization.

643610042241 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 214536680750.

The product of its (nonzero) digits is 27648, while the sum is 33.

Adding to 643610042241 its reverse (142240016346), we get a palindrome (785850058587).

The spelling of 643610042241 in words is "six hundred forty-three billion, six hundred ten million, forty-two thousand, two hundred forty-one".