100221931 has 2 divisors, whose sum is σ = 100221932. Its totient is φ = 100221930.

The previous prime is 100221929. The next prime is 100221983. The reversal of 100221931 is 139122001.

It is a weak prime.

It is an emirp because it is prime and its reverse (139122001) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 100221931 - 2¹ = 100221929 is a prime.

It is a super-2 number, since 2×100221931² = 20088870906737522, which contains 22 as substring.

Together with 100221929, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 100221899 and 100221908.

It is not a weakly prime, because it can be changed into another prime (100221911) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 50110965 + 50110966.

It is an arithmetic number, because the mean of its divisors is an integer number (50110966).

Almost surely, 2^100221931 is an apocalyptic number.

100221931 is a deficient number, since it is larger than the sum of its proper divisors (1).

100221931 is an equidigital number, since it uses as much as digits as its factorization.

100221931 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 108, while the sum is 19.

The square root of 100221931 is about 10011.0904001512. The cubic root of 100221931 is about 464.5020004757.

Adding to 100221931 its reverse (139122001), we get a palindrome (239343932).

The spelling of 100221931 in words is "one hundred million, two hundred twenty-one thousand, nine hundred thirty-one".