22390981 has 2 divisors, whose sum is σ = 22390982. Its totient is φ = 22390980.

The previous prime is 22390969. The next prime is 22390997. The reversal of 22390981 is 18909322.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14182756 + 8208225 = 3766^2 + 2865^2 .

It is a cyclic number.

It is not a de Polignac number, because 22390981 - 2¹⁹ = 21866693 is a prime.

It is a super-2 number, since 2×22390981² = 1002712060284722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (22390681) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 11195490 + 11195491.

It is an arithmetic number, because the mean of its divisors is an integer number (11195491).

Almost surely, 2^22390981 is an apocalyptic number.

It is an amenable number.

22390981 is a deficient number, since it is larger than the sum of its proper divisors (1).

22390981 is an equidigital number, since it uses as much as digits as its factorization.

22390981 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 7776, while the sum is 34.

The square root of 22390981 is about 4731.9109247745. The cubic root of 22390981 is about 281.8541111162.

It can be divided in two parts, 223 and 90981, that added together give a square (91204 = 302²).

The spelling of 22390981 in words is "twenty-two million, three hundred ninety thousand, nine hundred eighty-one".