2128661 has 8 divisors (see below), whose sum is σ = 2191200. Its totient is φ = 2067120.

The previous prime is 2128649. The next prime is 2128663. The reversal of 2128661 is 1668212.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 2128661 - 2¹⁸ = 1866517 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 2128661.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2128663) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6266 + ... + 6596.

It is an arithmetic number, because the mean of its divisors is an integer number (273900).

2^2128661 is an apocalyptic number.

It is an amenable number.

2128661 is a deficient number, since it is larger than the sum of its proper divisors (62539).

2128661 is a wasteful number, since it uses less digits than its factorization.

2128661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 499.

The product of its digits is 1152, while the sum is 26.

The square root of 2128661 is about 1458.9931459743. The cubic root of 2128661 is about 128.6378682479.

It can be divided in two parts, 21 and 28661, that added together give a palindrome (28682).

The spelling of 2128661 in words is "two million, one hundred twenty-eight thousand, six hundred sixty-one".