638796449 has 4 divisors (see below), whose sum is σ = 646882560. Its totient is φ = 630710340.

The previous prime is 638796413. The next prime is 638796451. The reversal of 638796449 is 944697836.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-638796449 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 638796394 and 638796403.

It is not an unprimeable number, because it can be changed into a prime (638796049) 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 3 ways as a sum of consecutive naturals, for example, 4042937 + ... + 4043094.

It is an arithmetic number, because the mean of its divisors is an integer number (161720640).

Almost surely, 2^638796449 is an apocalyptic number.

It is an amenable number.

638796449 is a deficient number, since it is larger than the sum of its proper divisors (8086111).

638796449 is an equidigital number, since it uses as much as digits as its factorization.

638796449 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8086110.

The product of its digits is 7838208, while the sum is 56.

The square root of 638796449 is about 25274.4228222921. The cubic root of 638796449 is about 861.2333345275.

The spelling of 638796449 in words is "six hundred thirty-eight million, seven hundred ninety-six thousand, four hundred forty-nine".