2102561 has 2 divisors, whose sum is σ = 2102562. Its totient is φ = 2102560.

The previous prime is 2102557. The next prime is 2102567. The reversal of 2102561 is 1652012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1547536 + 555025 = 1244^2 + 745^2 .

It is a cyclic number.

It is not a de Polignac number, because 2102561 - 2² = 2102557 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (2102567) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1051280 + 1051281.

It is an arithmetic number, because the mean of its divisors is an integer number (1051281).

2^2102561 is an apocalyptic number.

It is an amenable number.

2102561 is a deficient number, since it is larger than the sum of its proper divisors (1).

2102561 is an equidigital number, since it uses as much as digits as its factorization.

2102561 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 120, while the sum is 17.

The square root of 2102561 is about 1450.0210343302. The cubic root of 2102561 is about 128.1099519111.

Adding to 2102561 its reverse (1652012), we get a palindrome (3754573).

The spelling of 2102561 in words is "two million, one hundred two thousand, five hundred sixty-one".