643660113 has 8 divisors (see below), whose sum is σ = 864478368. Its totient is φ = 425974304.

The previous prime is 643660109. The next prime is 643660117. The reversal of 643660113 is 311066346.

It is an interprime number because it is at equal distance from previous prime (643660109) and next prime (643660117).

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 643660113 - 2² = 643660109 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (643660117) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 782631 + ... + 783452.

It is an arithmetic number, because the mean of its divisors is an integer number (108059796).

Almost surely, 2^643660113 is an apocalyptic number.

It is an amenable number.

643660113 is a deficient number, since it is larger than the sum of its proper divisors (220818255).

643660113 is a wasteful number, since it uses less digits than its factorization.

643660113 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1566223.

The product of its (nonzero) digits is 7776, while the sum is 30.

The square root of 643660113 is about 25370.4574850356. The cubic root of 643660113 is about 863.4135613972.

The spelling of 643660113 in words is "six hundred forty-three million, six hundred sixty thousand, one hundred thirteen".