22213981 has 2 divisors, whose sum is σ = 22213982. Its totient is φ = 22213980.

The previous prime is 22213979. The next prime is 22213991. The reversal of 22213981 is 18931222.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20169081 + 2044900 = 4491^2 + 1430^2 .

It is a cyclic number.

It is not a de Polignac number, because 22213981 - 2¹ = 22213979 is a prime.

It is a super-2 number, since 2×22213981² = 986921903736722, which contains 22 as substring.

Together with 22213979, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (22213921) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 11106990 + 11106991.

It is an arithmetic number, because the mean of its divisors is an integer number (11106991).

Almost surely, 2^22213981 is an apocalyptic number.

It is an amenable number.

22213981 is a deficient number, since it is larger than the sum of its proper divisors (1).

22213981 is an equidigital number, since it uses as much as digits as its factorization.

22213981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1728, while the sum is 28.

The square root of 22213981 is about 4713.1710132351. The cubic root of 22213981 is about 281.1094628899.

The spelling of 22213981 in words is "twenty-two million, two hundred thirteen thousand, nine hundred eighty-one".