1211440543 has 4 divisors (see below), whose sum is σ = 1215262440. Its totient is φ = 1207618648.

The previous prime is 1211440493. The next prime is 1211440583. The reversal of 1211440543 is 3450441121.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 3450441121 = 3989 ⋅864989.

It is a cyclic number.

It is not a de Polignac number, because 1211440543 - 2¹³ = 1211432351 is a prime.

It is a super-3 number, since 3×1211440543³ (a number of 28 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1211440583) 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, 1910473 + ... + 1911106.

It is an arithmetic number, because the mean of its divisors is an integer number (303815610).

Almost surely, 2^1211440543 is an apocalyptic number.

1211440543 is a deficient number, since it is larger than the sum of its proper divisors (3821897).

1211440543 is an equidigital number, since it uses as much as digits as its factorization.

1211440543 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3821896.

The product of its (nonzero) digits is 1920, while the sum is 25.

The square root of 1211440543 is about 34805.7544523890. The cubic root of 1211440543 is about 1066.0249467038.

Adding to 1211440543 its reverse (3450441121), we get a palindrome (4661881664).

The spelling of 1211440543 in words is "one billion, two hundred eleven million, four hundred forty thousand, five hundred forty-three".