22117681 has 2 divisors, whose sum is σ = 22117682. Its totient is φ = 22117680.

The previous prime is 22117679. The next prime is 22117723. The reversal of 22117681 is 18671122.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21077281 + 1040400 = 4591^2 + 1020^2 .

It is a cyclic number.

It is not a de Polignac number, because 22117681 - 2¹ = 22117679 is a prime.

It is a super-2 number, since 2×22117681² = 978383625635522, which contains 22 as substring.

Together with 22117679, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (22117621) 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, 11058840 + 11058841.

It is an arithmetic number, because the mean of its divisors is an integer number (11058841).

Almost surely, 2^22117681 is an apocalyptic number.

It is an amenable number.

22117681 is a deficient number, since it is larger than the sum of its proper divisors (1).

22117681 is an equidigital number, since it uses as much as digits as its factorization.

22117681 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1344, while the sum is 28.

The square root of 22117681 is about 4702.9438652827. The cubic root of 22117681 is about 280.7026612140.

The spelling of 22117681 in words is "twenty-two million, one hundred seventeen thousand, six hundred eighty-one".