643477520 has 80 divisors (see below), whose sum is σ = 1768815360. Its totient is φ = 213007872.

The previous prime is 643477511. The next prime is 643477529. The reversal of 643477520 is 25774346.

It is an interprime number because it is at equal distance from previous prime (643477511) and next prime (643477529).

It is a tau number, because it is divible by the number of its divisors (80).

It is not an unprimeable number, because it can be changed into a prime (643477529) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3572 + ... + 36051.

It is an arithmetic number, because the mean of its divisors is an integer number (22110192).

Almost surely, 2^643477520 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 643477520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (884407680).

643477520 is an abundant number, since it is smaller than the sum of its proper divisors (1125337840).

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

643477520 is a wasteful number, since it uses less digits than its factorization.

643477520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39672 (or 39666 counting only the distinct ones).

The product of its (nonzero) digits is 141120, while the sum is 38.

The square root of 643477520 is about 25366.8586939731. The cubic root of 643477520 is about 863.3319095133.

The spelling of 643477520 in words is "six hundred forty-three million, four hundred seventy-seven thousand, five hundred twenty".