643455930 has 32 divisors (see below), whose sum is σ = 1663087104. Its totient is φ = 158389056.

The previous prime is 643455929. The next prime is 643455931. The reversal of 643455930 is 39554346.

It is an interprime number because it is at equal distance from previous prime (643455929) and next prime (643455931).

It is a Harshad number since it is a multiple of its sum of digits (39).

It is not an unprimeable number, because it can be changed into a prime (643455931) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 824554 + ... + 825333.

It is an arithmetic number, because the mean of its divisors is an integer number (51971472).

Almost surely, 2^643455930 is an apocalyptic number.

643455930 is an abundant number, since it is smaller than the sum of its proper divisors (1019631174).

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

643455930 is a wasteful number, since it uses less digits than its factorization.

643455930 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1649910.

The product of its (nonzero) digits is 194400, while the sum is 39.

The square root of 643455930 is about 25366.4331351493. The cubic root of 643455930 is about 863.3222538824.

The spelling of 643455930 in words is "six hundred forty-three million, four hundred fifty-five thousand, nine hundred thirty".