643086816820 has 48 divisors (see below), whose sum is σ = 1543645450368. Its totient is φ = 220453038720.

The previous prime is 643086816817. The next prime is 643086816839. The reversal of 643086816820 is 28618680346.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 570414 + ... + 1269466.

It is an arithmetic number, because the mean of its divisors is an integer number (32159280216).

Almost surely, 2^643086816820 is an apocalyptic number.

It is an amenable number.

643086816820 is an abundant number, since it is smaller than the sum of its proper divisors (900558633548).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

643086816820 is a wasteful number, since it uses less digits than its factorization.

643086816820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 705640 (or 705638 counting only the distinct ones).

The product of its (nonzero) digits is 2654208, while the sum is 52.

The spelling of 643086816820 in words is "six hundred forty-three billion, eighty-six million, eight hundred sixteen thousand, eight hundred twenty".