22118015981 has 2 divisors, whose sum is σ = 22118015982. Its totient is φ = 22118015980.

The previous prime is 22118015891. The next prime is 22118015999. The reversal of 22118015981 is 18951081122.

Together with previous prime (22118015891) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17393653225 + 4724362756 = 131885^2 + 68734^2 .

It is a cyclic number.

It is not a de Polignac number, because 22118015981 - 2¹⁴ = 22117999597 is a prime.

It is a super-2 number, since 2×22118015981² (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 (22118015281) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 11059007990 + 11059007991.

It is an arithmetic number, because the mean of its divisors is an integer number (11059007991).

Almost surely, 2^22118015981 is an apocalyptic number.

It is an amenable number.

22118015981 is a deficient number, since it is larger than the sum of its proper divisors (1).

22118015981 is an equidigital number, since it uses as much as digits as its factorization.

22118015981 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 11520, while the sum is 38.

The spelling of 22118015981 in words is "twenty-two billion, one hundred eighteen million, fifteen thousand, nine hundred eighty-one".