2201681 has 2 divisors, whose sum is σ = 2201682.
Its totient is φ = 2201680.
The previous prime is 2201677. The next prime is 2201707. The reversal of 2201681 is 1861022.
It is a weak prime.
It can be written as a sum of positive squares in only one way, i.e., 1915456 + 286225 = 1384^2 + 535^2
It is a cyclic number.
It is not a de Polignac number, because 2201681 - 22 = 2201677 is a prime.
It is a super-2 number, since 2×22016812 = 9694798451522, which contains 22 as substring.
It is a Chen prime.
It is a congruent number.
It is not a weakly prime, because it can be changed into another prime (2201671) by changing a digit.
It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1100840 + 1100841.
It is an arithmetic number, because the mean of its divisors is an integer number (1100841).
22201681 is an apocalyptic number.
It is an amenable number.
2201681 is a deficient number, since it is larger than the sum of its proper divisors (1).
2201681 is an equidigital number, since it uses as much as digits as its factorization.
2201681 is an evil number, because the sum of its binary digits is even.
The product of its (nonzero) digits is 192, while the sum is 20.
The square root of 2201681 is about 1483.8062541990.
The cubic root of 2201681 is about 130.0922619217.
It can be divided in two parts, 2201 and 681, that added together give a palindrome (2882).
The spelling of 2201681 in words is "two million, two hundred one thousand, six hundred eighty-one".