643986258 has 16 divisors (see below), whose sum is σ = 1322783040. Its totient is φ = 208860336.

The previous prime is 643986257. The next prime is 643986263. The reversal of 643986258 is 852689346.

It is a self number, because there is not a number n which added to its sum of digits gives 643986258.

It is not an unprimeable number, because it can be changed into a prime (643986257) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1450198 + ... + 1450641.

It is an arithmetic number, because the mean of its divisors is an integer number (82673940).

Almost surely, 2^643986258 is an apocalyptic number.

643986258 is an abundant number, since it is smaller than the sum of its proper divisors (678796782).

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

643986258 is a wasteful number, since it uses less digits than its factorization.

643986258 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2900881.

The product of its digits is 2488320, while the sum is 51.

The square root of 643986258 is about 25376.8843241246. The cubic root of 643986258 is about 863.5593684059.

The spelling of 643986258 in words is "six hundred forty-three million, nine hundred eighty-six thousand, two hundred fifty-eight".