22180981 has 2 divisors, whose sum is σ = 22180982. Its totient is φ = 22180980.

The previous prime is 22180973. The next prime is 22180987. The reversal of 22180981 is 18908122.

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., 12780625 + 9400356 = 3575^2 + 3066^2 .

It is a cyclic number.

It is not a de Polignac number, because 22180981 - 2³ = 22180973 is a prime.

It is a super-2 number, since 2×22180981² = 983991836244722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (22180987) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 11090490 + 11090491.

It is an arithmetic number, because the mean of its divisors is an integer number (11090491).

Almost surely, 2^22180981 is an apocalyptic number.

It is an amenable number.

22180981 is a deficient number, since it is larger than the sum of its proper divisors (1).

22180981 is an equidigital number, since it uses as much as digits as its factorization.

22180981 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2304, while the sum is 31.

The square root of 22180981 is about 4709.6688843272. The cubic root of 22180981 is about 280.9701930956.

The spelling of 22180981 in words is "twenty-two million, one hundred eighty thousand, nine hundred eighty-one".