2165651 has 2 divisors, whose sum is σ = 2165652. Its totient is φ = 2165650.

The previous prime is 2165617. The next prime is 2165659. The reversal of 2165651 is 1565612.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2165651 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 2165651.

It is not a weakly prime, because it can be changed into another prime (2165659) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1082825 + 1082826.

It is an arithmetic number, because the mean of its divisors is an integer number (1082826).

2^2165651 is an apocalyptic number.

2165651 is a deficient number, since it is larger than the sum of its proper divisors (1).

2165651 is an equidigital number, since it uses as much as digits as its factorization.

2165651 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1800, while the sum is 26.

The square root of 2165651 is about 1471.6150991343. The cubic root of 2165651 is about 129.3787120377.

The spelling of 2165651 in words is "two million, one hundred sixty-five thousand, six hundred fifty-one".