643446145650 has 192 divisors, whose sum is σ = 1990042629120. Its totient is φ = 133666771200.

The previous prime is 643446145631. The next prime is 643446145669. The reversal of 643446145650 is 56541644346.

It is an interprime number because it is at equal distance from previous prime (643446145631) and next prime (643446145669).

It is a self number, because there is not a number n which added to its sum of digits gives 643446145650.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 72956941 + ... + 72965759.

It is an arithmetic number, because the mean of its divisors is an integer number (10364805360).

Almost surely, 2^643446145650 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 643446145650, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (995021314560).

643446145650 is an abundant number, since it is smaller than the sum of its proper divisors (1346596483470).

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

643446145650 is a wasteful number, since it uses less digits than its factorization.

643446145650 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15169 (or 15164 counting only the distinct ones).

The product of its (nonzero) digits is 4147200, while the sum is 48.

Adding to 643446145650 its reverse (56541644346), we get a palindrome (699987789996).

The spelling of 643446145650 in words is "six hundred forty-three billion, four hundred forty-six million, one hundred forty-five thousand, six hundred fifty".