643575040 has 144 divisors (see below), whose sum is σ = 1610606592. Its totient is φ = 246177792.

The previous prime is 643575013. The next prime is 643575041. The reversal of 643575040 is 40575346.

It is a happy number.

It is a super-2 number, since 2×643575040² = 828377664222003200, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 643574987 and 643575005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643575041) 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, 5067457 + ... + 5067583.

It is an arithmetic number, because the mean of its divisors is an integer number (11184768).

Almost surely, 2^643575040 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 643575040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (805303296).

643575040 is an abundant number, since it is smaller than the sum of its proper divisors (967031552).

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

643575040 is a wasteful number, since it uses less digits than its factorization.

643575040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 292 (or 278 counting only the distinct ones).

The product of its (nonzero) digits is 50400, while the sum is 34.

The square root of 643575040 is about 25368.7808142212. The cubic root of 643575040 is about 863.3755203997.

The spelling of 643575040 in words is "six hundred forty-three million, five hundred seventy-five thousand, forty".