643792641 has 4 divisors (see below), whose sum is σ = 858390192. Its totient is φ = 429195092.

The previous prime is 643792631. The next prime is 643792673. The reversal of 643792641 is 146297346.

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 643792641 - 2¹⁸ = 643530497 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 643792593 and 643792602.

It is not an unprimeable number, because it can be changed into a prime (643792631) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 107298771 + ... + 107298776.

It is an arithmetic number, because the mean of its divisors is an integer number (214597548).

Almost surely, 2^643792641 is an apocalyptic number.

It is an amenable number.

643792641 is a deficient number, since it is larger than the sum of its proper divisors (214597551).

643792641 is a wasteful number, since it uses less digits than its factorization.

643792641 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 214597550.

The product of its digits is 217728, while the sum is 42.

The square root of 643792641 is about 25373.0692073308. The cubic root of 643792641 is about 863.4728155583.

The spelling of 643792641 in words is "six hundred forty-three million, seven hundred ninety-two thousand, six hundred forty-one".