100021091 has 2 divisors, whose sum is σ = 100021092. Its totient is φ = 100021090.

The previous prime is 100021039. The next prime is 100021093. The reversal of 100021091 is 190120001.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 100021091 - 2¹⁸ = 99758947 is a prime.

Together with 100021093, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (100021093) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 50010545 + 50010546.

It is an arithmetic number, because the mean of its divisors is an integer number (50010546).

Almost surely, 2^100021091 is an apocalyptic number.

100021091 is a deficient number, since it is larger than the sum of its proper divisors (1).

100021091 is an equidigital number, since it uses as much as digits as its factorization.

100021091 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 18, while the sum is 14.

The square root of 100021091 is about 10001.0544944021. The cubic root of 100021091 is about 464.1915129841.

Adding to 100021091 its reverse (190120001), we get a palindrome (290141092).

The spelling of 100021091 in words is "one hundred million, twenty-one thousand, ninety-one".