2120111981 has 8 divisors (see below), whose sum is σ = 2287017600. Its totient is φ = 1953752112.

The previous prime is 2120111923. The next prime is 2120111993. The reversal of 2120111981 is 1891110212.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 2120111981 - 2¹⁰ = 2120110957 is a prime.

It is a super-2 number, since 2×2120111981² = 8989749623959488722, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 2120111981.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2120111921) 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, 128345 + ... + 143918.

It is an arithmetic number, because the mean of its divisors is an integer number (285877200).

Almost surely, 2^2120111981 is an apocalyptic number.

It is an amenable number.

2120111981 is a deficient number, since it is larger than the sum of its proper divisors (166905619).

2120111981 is a wasteful number, since it uses less digits than its factorization.

2120111981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 272875.

The product of its (nonzero) digits is 288, while the sum is 26.

The square root of 2120111981 is about 46044.6737527806. The cubic root of 2120111981 is about 1284.6542759208.

The spelling of 2120111981 in words is "two billion, one hundred twenty million, one hundred eleven thousand, nine hundred eighty-one".