643256250 has 288 divisors, whose sum is σ = 2058618240. Its totient is φ = 131040000.

The previous prime is 643256239. The next prime is 643256261. The reversal of 643256250 is 52652346.

It is an interprime number because it is at equal distance from previous prime (643256239) and next prime (643256261).

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 22181236 + ... + 22181264.

It is an arithmetic number, because the mean of its divisors is an integer number (7147980).

Almost surely, 2^643256250 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 643256250, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1029309120).

643256250 is an abundant number, since it is smaller than the sum of its proper divisors (1415361990).

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

643256250 is a wasteful number, since it uses less digits than its factorization.

643256250 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 92 (or 59 counting only the distinct ones).

The product of its (nonzero) digits is 43200, while the sum is 33.

The square root of 643256250 is about 25362.4969196647. The cubic root of 643256250 is about 863.2329413567.

The spelling of 643256250 in words is "six hundred forty-three million, two hundred fifty-six thousand, two hundred fifty".