643113540 has 48 divisors (see below), whose sum is σ = 2000799360. Its totient is φ = 171496800.

The previous prime is 643113533. The next prime is 643113571. The reversal of 643113540 is 45311346.

643113540 is a `hidden beast` number, since 6 + 4 + 3 + 113 + 540 = 666.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an unprimeable number.

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, 594936 + ... + 596015.

It is an arithmetic number, because the mean of its divisors is an integer number (41683320).

Almost surely, 2^643113540 is an apocalyptic number.

643113540 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

643113540 is an abundant number, since it is smaller than the sum of its proper divisors (1357685820).

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

643113540 is a wasteful number, since it uses less digits than its factorization.

643113540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1190969 (or 1190961 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 27.

The square root of 643113540 is about 25359.6833576447. The cubic root of 643113540 is about 863.1690989484.

Adding to 643113540 its reverse (45311346), we get a palindrome (688424886).

The spelling of 643113540 in words is "six hundred forty-three million, one hundred thirteen thousand, five hundred forty".