2164681 has 2 divisors, whose sum is σ = 2164682. Its totient is φ = 2164680.

The previous prime is 2164639. The next prime is 2164739. The reversal of 2164681 is 1864612.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1550025 + 614656 = 1245^2 + 784^2 .

It is a cyclic number.

It is not a de Polignac number, because 2164681 - 2¹⁷ = 2033609 is a prime.

It is a super-4 number, since 4×2164681⁴ (a number of 26 digits) contains 4444 as substring. Note that it is a super-d number also for d = 2.

It is a Chen prime.

2164681 is a lucky number.

It is not a weakly prime, because it can be changed into another prime (2164621) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1082340 + 1082341.

It is an arithmetic number, because the mean of its divisors is an integer number (1082341).

2^2164681 is an apocalyptic number.

It is an amenable number.

2164681 is a deficient number, since it is larger than the sum of its proper divisors (1).

2164681 is an equidigital number, since it uses as much as digits as its factorization.

2164681 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2304, while the sum is 28.

The square root of 2164681 is about 1471.2854923501. The cubic root of 2164681 is about 129.3593928134.

The spelling of 2164681 in words is "two million, one hundred sixty-four thousand, six hundred eighty-one".