22101221981 has 2 divisors, whose sum is σ = 22101221982. Its totient is φ = 22101221980.

The previous prime is 22101221959. The next prime is 22101221999. The reversal of 22101221981 is 18912210122.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21459613081 + 641608900 = 146491^2 + 25330^2 .

It is a cyclic number.

It is not a de Polignac number, because 22101221981 - 2³⁰ = 21027480157 is a prime.

It is a super-2 number, since 2×22101221981² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (22101221921) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 11050610990 + 11050610991.

It is an arithmetic number, because the mean of its divisors is an integer number (11050610991).

Almost surely, 2^22101221981 is an apocalyptic number.

It is an amenable number.

22101221981 is a deficient number, since it is larger than the sum of its proper divisors (1).

22101221981 is an equidigital number, since it uses as much as digits as its factorization.

22101221981 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1152, while the sum is 29.

The spelling of 22101221981 in words is "twenty-two billion, one hundred one million, two hundred twenty-one thousand, nine hundred eighty-one".