100122821 has 2 divisors, whose sum is σ = 100122822. Its totient is φ = 100122820.

The previous prime is 100122797. The next prime is 100122833. The reversal of 100122821 is 128221001.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 95452900 + 4669921 = 9770^2 + 2161^2 .

It is an emirp because it is prime and its reverse (128221001) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 100122821 - 2²² = 95928517 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 100122821.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (100122881) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 50061410 + 50061411.

It is an arithmetic number, because the mean of its divisors is an integer number (50061411).

Almost surely, 2^100122821 is an apocalyptic number.

It is an amenable number.

100122821 is a deficient number, since it is larger than the sum of its proper divisors (1).

100122821 is an equidigital number, since it uses as much as digits as its factorization.

100122821 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 64, while the sum is 17.

The square root of 100122821 is about 10006.1391655323. The cubic root of 100122821 is about 464.3488338102.

Adding to 100122821 its reverse (128221001), we get a palindrome (228343822).

The spelling of 100122821 in words is "one hundred million, one hundred twenty-two thousand, eight hundred twenty-one".