638469009 has 24 divisors (see below), whose sum is σ = 945914112. Its totient is φ = 414794880.

The previous prime is 638468977. The next prime is 638469011. The reversal of 638469009 is 900964836.

638469009 is a `hidden beast` number, since 638 + 4 + 6 + 9 + 0 + 0 + 9 = 666.

It is not a de Polignac number, because 638469009 - 2⁵ = 638468977 is a prime.

It is not an unprimeable number, because it can be changed into a prime (638469049) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 98812 + ... + 105074.

It is an arithmetic number, because the mean of its divisors is an integer number (39413088).

Almost surely, 2^638469009 is an apocalyptic number.

It is an amenable number.

638469009 is a deficient number, since it is larger than the sum of its proper divisors (307445103).

638469009 is a wasteful number, since it uses less digits than its factorization.

638469009 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6557 (or 6554 counting only the distinct ones).

The product of its (nonzero) digits is 279936, while the sum is 45.

The square root of 638469009 is about 25267.9442970733. The cubic root of 638469009 is about 861.0861564810.

The spelling of 638469009 in words is "six hundred thirty-eight million, four hundred sixty-nine thousand, nine".