643047020 has 96 divisors (see below), whose sum is σ = 1772305920. Its totient is φ = 189872640.

The previous prime is 643046977. The next prime is 643047023. The reversal of 643047020 is 20740346.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (643047023) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 18272 + ... + 40248.

It is an arithmetic number, because the mean of its divisors is an integer number (18461520).

Almost surely, 2^643047020 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 643047020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (886152960).

643047020 is an abundant number, since it is smaller than the sum of its proper divisors (1129258900).

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

643047020 is a wasteful number, since it uses less digits than its factorization.

643047020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22023 (or 22021 counting only the distinct ones).

The product of its (nonzero) digits is 4032, while the sum is 26.

The square root of 643047020 is about 25358.3717931574. The cubic root of 643047020 is about 863.1393374912.

Adding to 643047020 its reverse (20740346), we get a palindrome (663787366).

The spelling of 643047020 in words is "six hundred forty-three million, forty-seven thousand, twenty".