643814460 has 96 divisors (see below), whose sum is σ = 2045675520. Its totient is φ = 168024384.

The previous prime is 643814443. The next prime is 643814477. The reversal of 643814460 is 64418346.

643814460 is a `hidden beast` number, since 643 + 8 + 1 + 4 + 4 + 6 + 0 = 666.

It is an interprime number because it is at equal distance from previous prime (643814443) and next prime (643814477).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 12697 + ... + 38063.

It is an arithmetic number, because the mean of its divisors is an integer number (21309120).

Almost surely, 2^643814460 is an apocalyptic number.

643814460 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 643814460, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1022837760).

643814460 is an abundant number, since it is smaller than the sum of its proper divisors (1401861060).

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

643814460 is a wasteful number, since it uses less digits than its factorization.

643814460 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25432 (or 25424 counting only the distinct ones).

The product of its (nonzero) digits is 55296, while the sum is 36.

The square root of 643814460 is about 25373.4991674385. The cubic root of 643814460 is about 863.4825702004.

The spelling of 643814460 in words is "six hundred forty-three million, eight hundred fourteen thousand, four hundred sixty".