643312157836 has 12 divisors (see below), whose sum is σ = 1128034443312. Its totient is φ = 321016602608.

The previous prime is 643312157827. The next prime is 643312157867. The reversal of 643312157836 is 638751213346.

It is a super-2 number, since 2×643312157836² (a number of 24 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 643312157836.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 159866815 + ... + 159870838.

It is an arithmetic number, because the mean of its divisors is an integer number (94002870276).

Almost surely, 2^643312157836 is an apocalyptic number.

It is an amenable number.

643312157836 is a deficient number, since it is larger than the sum of its proper divisors (484722285476).

643312157836 is a wasteful number, since it uses less digits than its factorization.

643312157836 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 319738160 (or 319738158 counting only the distinct ones).

The product of its digits is 2177280, while the sum is 49.

The spelling of 643312157836 in words is "six hundred forty-three billion, three hundred twelve million, one hundred fifty-seven thousand, eight hundred thirty-six".