1121906553 has 4 divisors (see below), whose sum is σ = 1495875408. Its totient is φ = 747937700.

The previous prime is 1121906543. The next prime is 1121906573. The reversal of 1121906553 is 3556091211.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 3556091211 = 3 ⋅1185363737.

It is a cyclic number.

It is not a de Polignac number, because 1121906553 - 2⁴ = 1121906537 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1121906543) 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, 186984423 + ... + 186984428.

It is an arithmetic number, because the mean of its divisors is an integer number (373968852).

Almost surely, 2^1121906553 is an apocalyptic number.

It is an amenable number.

1121906553 is a deficient number, since it is larger than the sum of its proper divisors (373968855).

1121906553 is an equidigital number, since it uses as much as digits as its factorization.

1121906553 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 373968854.

The product of its (nonzero) digits is 8100, while the sum is 33.

The square root of 1121906553 is about 33494.8735331244. The cubic root of 1121906553 is about 1039.0877580562.

Adding to 1121906553 its reverse (3556091211), we get a palindrome (4677997764).

The spelling of 1121906553 in words is "one billion, one hundred twenty-one million, nine hundred six thousand, five hundred fifty-three".