111001582561 has 9 divisors (see below), whose sum is σ = 111600827793. Its totient is φ = 110405543220.

The previous prime is 111001582547. The next prime is 111001582619. The reversal of 111001582561 is 165285100111.

The square root of 111001582561 is 333169.

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

It is not a de Polignac number, because 111001582561 - 2⁵ = 111001582529 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (111001582261) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 70297870 + ... + 70299448.

It is an arithmetic number, because the mean of its divisors is an integer number (12400091977).

Almost surely, 2^111001582561 is an apocalyptic number.

111001582561 is the 333169-th square number.

111001582561 is the 166585-th centered octagonal number.

It is an amenable number.

111001582561 is a deficient number, since it is larger than the sum of its proper divisors (599245232).

111001582561 is an frugal number, since it uses more digits than its factorization.

111001582561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3580 (or 1790 counting only the distinct ones).

The product of its (nonzero) digits is 2400, while the sum is 31.

Adding to 111001582561 its reverse (165285100111), we get a palindrome (276286682672).

The spelling of 111001582561 in words is "one hundred eleven billion, one million, five hundred eighty-two thousand, five hundred sixty-one".