2666021 has 2 divisors, whose sum is σ = 2666022. Its totient is φ = 2666020.

The previous prime is 2665973. The next prime is 2666029. The reversal of 2666021 is 1206662.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2217121 + 448900 = 1489^2 + 670^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2666021 is a prime.

It is a Chen prime.

It is a magnanimous number.

It is equal to p₁₉₄₃₆₀ and since 2666021 and 194360 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2666029) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1333010 + 1333011.

It is an arithmetic number, because the mean of its divisors is an integer number (1333011).

2^2666021 is an apocalyptic number.

It is an amenable number.

2666021 is a deficient number, since it is larger than the sum of its proper divisors (1).

2666021 is an equidigital number, since it uses as much as digits as its factorization.

2666021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 864, while the sum is 23.

The square root of 2666021 is about 1632.7954556527. The cubic root of 2666021 is about 138.6610619601.

The spelling of 2666021 in words is "two million, six hundred sixty-six thousand, twenty-one".