111071887721 has 4 divisors (see below), whose sum is σ = 111779352132. Its totient is φ = 110364423312.

The previous prime is 111071887699. The next prime is 111071887747. The reversal of 111071887721 is 127788170111.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 26483982121 + 84587905600 = 162739^2 + 290840^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-111071887721 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 (111071887621) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 353731970 + ... + 353732283.

It is an arithmetic number, because the mean of its divisors is an integer number (27944838033).

Almost surely, 2^111071887721 is an apocalyptic number.

It is an amenable number.

111071887721 is a deficient number, since it is larger than the sum of its proper divisors (707464411).

111071887721 is an equidigital number, since it uses as much as digits as its factorization.

111071887721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 707464410.

The product of its (nonzero) digits is 43904, while the sum is 44.

The spelling of 111071887721 in words is "one hundred eleven billion, seventy-one million, eight hundred eighty-seven thousand, seven hundred twenty-one".