2123557 has 2 divisors, whose sum is σ = 2123558. Its totient is φ = 2123556.

The previous prime is 2123491. The next prime is 2123581. The reversal of 2123557 is 7553212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1846881 + 276676 = 1359^2 + 526^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2123557 is a prime.

It is a d-powerful number, because it can be written as 2⁷ + 1 + 2²¹ + 3⁹ + 5⁵ + 5⁵ + 7³ .

It is equal to p₁₅₇₄₂₆ and since 2123557 and 157426 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 (2123257) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1061778 + 1061779.

It is an arithmetic number, because the mean of its divisors is an integer number (1061779).

2^2123557 is an apocalyptic number.

It is an amenable number.

2123557 is a deficient number, since it is larger than the sum of its proper divisors (1).

2123557 is an equidigital number, since it uses as much as digits as its factorization.

2123557 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2100, while the sum is 25.

The square root of 2123557 is about 1457.2429447419. The cubic root of 2123557 is about 128.5349720858.

Adding to 2123557 its reverse (7553212), we get a palindrome (9676769).

The spelling of 2123557 in words is "two million, one hundred twenty-three thousand, five hundred fifty-seven".