643503043461 has 4 divisors (see below), whose sum is σ = 858004057952. Its totient is φ = 429002028972.

The previous prime is 643503043429. The next prime is 643503043489. The reversal of 643503043461 is 164340305346.

643503043461 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 not a de Polignac number, because 643503043461 - 2⁵ = 643503043429 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643503043061) 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, 107250507241 + ... + 107250507246.

It is an arithmetic number, because the mean of its divisors is an integer number (214501014488).

Almost surely, 2^643503043461 is an apocalyptic number.

It is an amenable number.

643503043461 is a deficient number, since it is larger than the sum of its proper divisors (214501014491).

643503043461 is a wasteful number, since it uses less digits than its factorization.

643503043461 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 214501014490.

The product of its (nonzero) digits is 311040, while the sum is 39.

The spelling of 643503043461 in words is "six hundred forty-three billion, five hundred three million, forty-three thousand, four hundred sixty-one".