643403877 has 4 divisors (see below), whose sum is σ = 857871840. Its totient is φ = 428935916.

The previous prime is 643403861. The next prime is 643403921. The reversal of 643403877 is 778304346.

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 643403877 - 2⁴ = 643403861 is a prime.

It is a super-2 number, since 2×643403877² = 827937097877262258, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643403177) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 107233977 + ... + 107233982.

It is an arithmetic number, because the mean of its divisors is an integer number (214467960).

Almost surely, 2^643403877 is an apocalyptic number.

It is an amenable number.

643403877 is a deficient number, since it is larger than the sum of its proper divisors (214467963).

643403877 is a wasteful number, since it uses less digits than its factorization.

643403877 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 214467962.

The product of its (nonzero) digits is 338688, while the sum is 42.

The square root of 643403877 is about 25365.4070931259. The cubic root of 643403877 is about 863.2989734871.

The spelling of 643403877 in words is "six hundred forty-three million, four hundred three thousand, eight hundred seventy-seven".