2128669 has 2 divisors, whose sum is σ = 2128670. Its totient is φ = 2128668.

The previous prime is 2128667. The next prime is 2128697. The reversal of 2128669 is 9668212.

It is a happy number.

2128669 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1102500 + 1026169 = 1050^2 + 1013^2 .

It is a cyclic number.

It is not a de Polignac number, because 2128669 - 2¹ = 2128667 is a prime.

It is a super-2 number, since 2×2128669² = 9062463423122, which contains 22 as substring.

Together with 2128667, it forms a pair of twin primes.

2128669 is a lucky number.

It is equal to p₁₅₇₇₈₆ and since 2128669 and 157786 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 (2128663) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1064334 + 1064335.

It is an arithmetic number, because the mean of its divisors is an integer number (1064335).

2^2128669 is an apocalyptic number.

It is an amenable number.

2128669 is a deficient number, since it is larger than the sum of its proper divisors (1).

2128669 is an equidigital number, since it uses as much as digits as its factorization.

2128669 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 10368, while the sum is 34.

The square root of 2128669 is about 1458.9958875884. The cubic root of 2128669 is about 128.6380293980.

The spelling of 2128669 in words is "two million, one hundred twenty-eight thousand, six hundred sixty-nine".