111520721 has 8 divisors (see below), whose sum is σ = 125321280. Its totient is φ = 98466192.

The previous prime is 111520699. The next prime is 111520723. The reversal of 111520721 is 127025111.

It is a happy number.

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 111520721 - 2¹⁰ = 111519697 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 111520693 and 111520702.

It is not an unprimeable number, because it can be changed into a prime (111520723) 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, 186191 + ... + 186788.

It is an arithmetic number, because the mean of its divisors is an integer number (15665160).

Almost surely, 2^111520721 is an apocalyptic number.

It is an amenable number.

111520721 is a deficient number, since it is larger than the sum of its proper divisors (13800559).

111520721 is a wasteful number, since it uses less digits than its factorization.

111520721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 373015.

The product of its (nonzero) digits is 140, while the sum is 20.

The square root of 111520721 is about 10560.3371631781. The cubic root of 111520721 is about 481.3398919955.

Adding to 111520721 its reverse (127025111), we get a palindrome (238545832).

The spelling of 111520721 in words is "one hundred eleven million, five hundred twenty thousand, seven hundred twenty-one".