640438193 has 8 divisors (see below), whose sum is σ = 653640480. Its totient is φ = 627343200.

The previous prime is 640438189. The next prime is 640438219. The reversal of 640438193 is 391834046.

640438193 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 640438193 - 2² = 640438189 is a prime.

It is a super-2 number, since 2×640438193² = 820322158106210498, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (640438103) 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, 14708 + ... + 38693.

It is an arithmetic number, because the mean of its divisors is an integer number (81705060).

Almost surely, 2^640438193 is an apocalyptic number.

It is an amenable number.

640438193 is a deficient number, since it is larger than the sum of its proper divisors (13202287).

640438193 is a wasteful number, since it uses less digits than its factorization.

640438193 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 53647.

The product of its (nonzero) digits is 62208, while the sum is 38.

The square root of 640438193 is about 25306.8803490276. The cubic root of 640438193 is about 861.9705099344.

The spelling of 640438193 in words is "six hundred forty million, four hundred thirty-eight thousand, one hundred ninety-three".