100021229981 has 2 divisors, whose sum is σ = 100021229982. Its totient is φ = 100021229980.

The previous prime is 100021229929. The next prime is 100021230103. The reversal of 100021229981 is 189922120001.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 50314527481 + 49706702500 = 224309^2 + 222950^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-100021229981 is a prime.

It is a super-2 number, since 2×100021229981² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (100021229911) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 50010614990 + 50010614991.

It is an arithmetic number, because the mean of its divisors is an integer number (50010614991).

Almost surely, 2^100021229981 is an apocalyptic number.

It is an amenable number.

100021229981 is a deficient number, since it is larger than the sum of its proper divisors (1).

100021229981 is an equidigital number, since it uses as much as digits as its factorization.

100021229981 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5184, while the sum is 35.

Adding to 100021229981 its reverse (189922120001), we get a palindrome (289943349982).

The spelling of 100021229981 in words is "one hundred billion, twenty-one million, two hundred twenty-nine thousand, nine hundred eighty-one".