2143561 has 16 divisors (see below), whose sum is σ = 2626560. Its totient is φ = 1708560.

The previous prime is 2143543. The next prime is 2143567. The reversal of 2143561 is 1653412.

It is not a de Polignac number, because 2143561 - 2¹³ = 2135369 is a prime.

It is not an unprimeable number, because it can be changed into a prime (2143567) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9330 + ... + 9556.

It is an arithmetic number, because the mean of its divisors is an integer number (164160).

2^2143561 is an apocalyptic number.

It is an amenable number.

2143561 is a deficient number, since it is larger than the sum of its proper divisors (482999).

2143561 is a wasteful number, since it uses less digits than its factorization.

2143561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 324.

The product of its digits is 720, while the sum is 22.

The square root of 2143561 is about 1464.0905026671. The cubic root of 2143561 is about 128.9373130515.

Adding to 2143561 its reverse (1653412), we get a palindrome (3796973).

It can be divided in two parts, 2143 and 561, that added together give a square (2704 = 52²).

The spelling of 2143561 in words is "two million, one hundred forty-three thousand, five hundred sixty-one".