638228811 has 8 divisors (see below), whose sum is σ = 928332864. Its totient is φ = 386805320.

The previous prime is 638228779. The next prime is 638228813. The reversal of 638228811 is 118822836.

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

It is not a de Polignac number, because 638228811 - 2⁵ = 638228779 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 638228811.

It is not an unprimeable number, because it can be changed into a prime (638228813) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9670101 + ... + 9670166.

It is an arithmetic number, because the mean of its divisors is an integer number (116041608).

Almost surely, 2^638228811 is an apocalyptic number.

638228811 is a deficient number, since it is larger than the sum of its proper divisors (290104053).

638228811 is a wasteful number, since it uses less digits than its factorization.

638228811 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19340281.

The product of its digits is 36864, while the sum is 39.

The square root of 638228811 is about 25263.1908317220. The cubic root of 638228811 is about 860.9781600539.

The spelling of 638228811 in words is "six hundred thirty-eight million, two hundred twenty-eight thousand, eight hundred eleven".