1123788721 has 16 divisors (see below), whose sum is σ = 1268338176. Its totient is φ = 986800000.

The previous prime is 1123788707. The next prime is 1123788727. The reversal of 1123788721 is 1278873211.

It is a cyclic number.

It is not a de Polignac number, because 1123788721 - 2⁷ = 1123788593 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1123788727) 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, 33216 + ... + 57886.

It is an arithmetic number, because the mean of its divisors is an integer number (79271136).

Almost surely, 2^1123788721 is an apocalyptic number.

1123788721 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1123788721 is a deficient number, since it is larger than the sum of its proper divisors (144549455).

1123788721 is a wasteful number, since it uses less digits than its factorization.

1123788721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24824.

The product of its digits is 37632, while the sum is 40.

The square root of 1123788721 is about 33522.9581182807. The cubic root of 1123788721 is about 1039.6685090580.

It can be divided in two parts, 11 and 23788721, that added together give a palindrome (23788732).

The spelling of 1123788721 in words is "one billion, one hundred twenty-three million, seven hundred eighty-eight thousand, seven hundred twenty-one".