2123531 has 4 divisors (see below), whose sum is σ = 2192064. Its totient is φ = 2055000.

The previous prime is 2123491. The next prime is 2123557. The reversal of 2123531 is 1353212.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 2123531 - 2¹⁰ = 2122507 is a prime.

It is a super-2 number, since 2×2123531² = 9018767815922, which contains 22 as substring.

It is a d-powerful number, because it can be written as 2⁷ + 1 + 2²¹ + 3⁸ + 5 + 3⁹ + 1 .

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2123581) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 34220 + ... + 34281.

It is an arithmetic number, because the mean of its divisors is an integer number (548016).

2^2123531 is an apocalyptic number.

2123531 is a deficient number, since it is larger than the sum of its proper divisors (68533).

2123531 is an equidigital number, since it uses as much as digits as its factorization.

2123531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 68532.

The product of its digits is 180, while the sum is 17.

The square root of 2123531 is about 1457.2340237587. The cubic root of 2123531 is about 128.5344475064.

Adding to 2123531 its reverse (1353212), we get a palindrome (3476743).

The spelling of 2123531 in words is "two million, one hundred twenty-three thousand, five hundred thirty-one".