111921695209 has 3 divisors (see below), whose sum is σ = 111922029757. Its totient is φ = 111921360662.

The previous prime is 111921695191. The next prime is 111921695219. The reversal of 111921695209 is 902596129111.

The square root of 111921695209 is 334547.

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

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 902596129111 = 647 ⋅1395048113.

It is not a de Polignac number, because 111921695209 - 2⁵ = 111921695177 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (111921695219) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 167274 + ... + 501820.

Almost surely, 2^111921695209 is an apocalyptic number.

111921695209 is the 334547-th square number.

111921695209 is the 167274-th centered octagonal number.

It is an amenable number.

111921695209 is a deficient number, since it is larger than the sum of its proper divisors (334548).

111921695209 is an frugal number, since it uses more digits than its factorization.

111921695209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 669094 (or 334547 counting only the distinct ones).

The product of its (nonzero) digits is 87480, while the sum is 46.

The spelling of 111921695209 in words is "one hundred eleven billion, nine hundred twenty-one million, six hundred ninety-five thousand, two hundred nine".