1211540023 has 2 divisors, whose sum is σ = 1211540024. Its totient is φ = 1211540022.

The previous prime is 1211540021. The next prime is 1211540027. The reversal of 1211540023 is 3200451121.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1211540023 - 2¹ = 1211540021 is a prime.

Together with 1211540021, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1211540021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 605770011 + 605770012.

It is an arithmetic number, because the mean of its divisors is an integer number (605770012).

Almost surely, 2^1211540023 is an apocalyptic number.

1211540023 is a deficient number, since it is larger than the sum of its proper divisors (1).

1211540023 is an equidigital number, since it uses as much as digits as its factorization.

1211540023 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 240, while the sum is 19.

The square root of 1211540023 is about 34807.1834970886. The cubic root of 1211540023 is about 1066.0541255355.

Adding to 1211540023 its reverse (3200451121), we get a palindrome (4411991144).

The spelling of 1211540023 in words is "one billion, two hundred eleven million, five hundred forty thousand, twenty-three".