643347620 has 24 divisors (see below), whose sum is σ = 1353065784. Its totient is φ = 256951296.

The previous prime is 643347611. The next prime is 643347637. The reversal of 643347620 is 26743346.

It can be written as a sum of positive squares in 4 ways, for example, as 31181056 + 612166564 = 5584^2 + 24742^2 .

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 10439 + ... + 37358.

It is an arithmetic number, because the mean of its divisors is an integer number (56377741).

Almost surely, 2^643347620 is an apocalyptic number.

It is an amenable number.

643347620 is an abundant number, since it is smaller than the sum of its proper divisors (709718164).

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

643347620 is a wasteful number, since it uses less digits than its factorization.

643347620 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 48479 (or 48477 counting only the distinct ones).

The product of its (nonzero) digits is 72576, while the sum is 35.

The square root of 643347620 is about 25364.2981373426. The cubic root of 643347620 is about 863.2738114660.

The spelling of 643347620 in words is "six hundred forty-three million, three hundred forty-seven thousand, six hundred twenty".