638229665 has 16 divisors (see below), whose sum is σ = 807381120. Its totient is φ = 482993280.

The previous prime is 638229653. The next prime is 638229667. The reversal of 638229665 is 566922836.

It is not a de Polignac number, because 638229665 - 2⁶ = 638229601 is a prime.

It is a Smith number, since the sum of its digits (47) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (638229667) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 64445 + ... + 73685.

It is an arithmetic number, because the mean of its divisors is an integer number (50461320).

Almost surely, 2^638229665 is an apocalyptic number.

It is an amenable number.

638229665 is a deficient number, since it is larger than the sum of its proper divisors (169151455).

638229665 is a wasteful number, since it uses less digits than its factorization.

638229665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9992.

The product of its digits is 933120, while the sum is 47.

The square root of 638229665 is about 25263.2077337776. The cubic root of 638229665 is about 860.9785440724.

The spelling of 638229665 in words is "six hundred thirty-eight million, two hundred twenty-nine thousand, six hundred sixty-five".