100638909 has 32 divisors (see below), whose sum is σ = 170864640. Its totient is φ = 57349296.

The previous prime is 100638899. The next prime is 100638913. The reversal of 100638909 is 909836001.

100638909 is a `hidden beast` number, since 10 + 0 + 638 + 9 + 0 + 9 = 666.

It is not a de Polignac number, because 100638909 - 2⁴ = 100638893 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (100638509) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 121872 + ... + 122694.

It is an arithmetic number, because the mean of its divisors is an integer number (5339520).

Almost surely, 2^100638909 is an apocalyptic number.

It is an amenable number.

100638909 is a deficient number, since it is larger than the sum of its proper divisors (70225731).

100638909 is an equidigital number, since it uses as much as digits as its factorization.

100638909 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1486 (or 1480 counting only the distinct ones).

The product of its (nonzero) digits is 11664, while the sum is 36.

The square root of 100638909 is about 10031.8945867667. The cubic root of 100638909 is about 465.1453031861.

The spelling of 100638909 in words is "one hundred million, six hundred thirty-eight thousand, nine hundred nine".