1121716721 has 8 divisors (see below), whose sum is σ = 1126929024. Its totient is φ = 1116517360.

The previous prime is 1121716709. The next prime is 1121716727. The reversal of 1121716721 is 1276171211.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1121716721 - 2²⁶ = 1054607857 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1121716727) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 198491 + ... + 204063.

It is an arithmetic number, because the mean of its divisors is an integer number (140866128).

Almost surely, 2^1121716721 is an apocalyptic number.

It is an amenable number.

1121716721 is a deficient number, since it is larger than the sum of its proper divisors (5212303).

1121716721 is an equidigital number, since it uses as much as digits as its factorization.

1121716721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6471.

The product of its digits is 1176, while the sum is 29.

The square root of 1121716721 is about 33492.0396661655. The cubic root of 1121716721 is about 1039.0291485303.

Adding to 1121716721 its reverse (1276171211), we get a palindrome (2397887932).

The spelling of 1121716721 in words is "one billion, one hundred twenty-one million, seven hundred sixteen thousand, seven hundred twenty-one".