643025550 has 96 divisors (see below), whose sum is σ = 1719889920. Its totient is φ = 158457600.

The previous prime is 643025549. The next prime is 643025557. The reversal of 643025550 is 55520346.

643025550 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643025557) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 114099 + ... + 119601.

It is an arithmetic number, because the mean of its divisors is an integer number (17915520).

Almost surely, 2^643025550 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 643025550, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (859944960).

643025550 is an abundant number, since it is smaller than the sum of its proper divisors (1076864370).

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

643025550 is a wasteful number, since it uses less digits than its factorization.

643025550 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5578 (or 5573 counting only the distinct ones).

The product of its (nonzero) digits is 18000, while the sum is 30.

The square root of 643025550 is about 25357.9484580279. The cubic root of 643025550 is about 863.1297312430.

Adding to 643025550 its reverse (55520346), we get a palindrome (698545896).

The spelling of 643025550 in words is "six hundred forty-three million, twenty-five thousand, five hundred fifty".