11223071721 has 45 divisors (see below), whose sum is σ = 17094961191. Its totient is φ = 7337758896.

The previous prime is 11223071689. The next prime is 11223071723. The reversal of 11223071721 is 12717032211.

The square root of 11223071721 is 105939.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 1314860121 + 9908211600 = 36261^2 + 99540^2 .

It is not a de Polignac number, because 11223071721 - 2⁵ = 11223071689 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (11223071723) by changing a digit.

It is a polite number, since it can be written in 44 ways as a sum of consecutive naturals, for example, 75322555 + ... + 75322703.

Almost surely, 2^11223071721 is an apocalyptic number.

11223071721 is the 105939-th square number.

11223071721 is the 52970-th centered octagonal number.

It is an amenable number.

11223071721 is a deficient number, since it is larger than the sum of its proper divisors (5871889470).

11223071721 is an frugal number, since it uses more digits than its factorization.

11223071721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 468 (or 231 counting only the distinct ones).

The product of its (nonzero) digits is 1176, while the sum is 27.

The spelling of 11223071721 in words is "eleven billion, two hundred twenty-three million, seventy-one thousand, seven hundred twenty-one".