643331040 has 96 divisors (see below), whose sum is σ = 2210737536. Its totient is φ = 155957760.

The previous prime is 643331027. The next prime is 643331053. The reversal of 643331040 is 40133346.

It is an interprime number because it is at equal distance from previous prime (643331027) and next prime (643331053).

It is a tau number, because it is divible by the number of its divisors (96).

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a self number, because there is not a number n which added to its sum of digits gives 643331040.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 55642 + ... + 66201.

It is an arithmetic number, because the mean of its divisors is an integer number (23028516).

Almost surely, 2^643331040 is an apocalyptic number.

643331040 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

643331040 is an abundant number, since it is smaller than the sum of its proper divisors (1567406496).

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

643331040 is a wasteful number, since it uses less digits than its factorization.

643331040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 121872 (or 121864 counting only the distinct ones).

The product of its (nonzero) digits is 2592, while the sum is 24.

The square root of 643331040 is about 25363.9712978863. The cubic root of 643331040 is about 863.2663954634.

Adding to 643331040 its reverse (40133346), we get a palindrome (683464386).

It can be divided in two parts, 6433 and 31040, that added together give a palindrome (37473).

The spelling of 643331040 in words is "six hundred forty-three million, three hundred thirty-one thousand, forty".