100909381 has 2 divisors, whose sum is σ = 100909382. Its totient is φ = 100909380.

The previous prime is 100909379. The next prime is 100909387. The reversal of 100909381 is 183909001.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 55130625 + 45778756 = 7425^2 + 6766^2 .

It is a cyclic number.

It is not a de Polignac number, because 100909381 - 2¹ = 100909379 is a prime.

It is a super-2 number, since 2×100909381² = 20365406347606322, which contains 22 as substring.

Together with 100909379, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (100909387) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 50454690 + 50454691.

It is an arithmetic number, because the mean of its divisors is an integer number (50454691).

Almost surely, 2^100909381 is an apocalyptic number.

It is an amenable number.

100909381 is a deficient number, since it is larger than the sum of its proper divisors (1).

100909381 is an equidigital number, since it uses as much as digits as its factorization.

100909381 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1944, while the sum is 31.

The square root of 100909381 is about 10045.3661456415. The cubic root of 100909381 is about 465.5616307077.

The spelling of 100909381 in words is "one hundred million, nine hundred nine thousand, three hundred eighty-one".