638841345 has 8 divisors (see below), whose sum is σ = 1022146176. Its totient is φ = 340715376.

The previous prime is 638841341. The next prime is 638841373. The reversal of 638841345 is 543148836.

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

It is not a de Polignac number, because 638841345 - 2² = 638841341 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 638841297 and 638841306.

It is not an unprimeable number, because it can be changed into a prime (638841341) 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, 21294697 + ... + 21294726.

It is an arithmetic number, because the mean of its divisors is an integer number (127768272).

Almost surely, 2^638841345 is an apocalyptic number.

It is an amenable number.

638841345 is a deficient number, since it is larger than the sum of its proper divisors (383304831).

638841345 is a wasteful number, since it uses less digits than its factorization.

638841345 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42589431.

The product of its digits is 276480, while the sum is 42.

The square root of 638841345 is about 25275.3109773154. The cubic root of 638841345 is about 861.2535105038.

The spelling of 638841345 in words is "six hundred thirty-eight million, eight hundred forty-one thousand, three hundred forty-five".