2112211981 has 4 divisors (see below), whose sum is σ = 2304231264. Its totient is φ = 1920192700.

The previous prime is 2112211967. The next prime is 2112212029. The reversal of 2112211981 is 1891122112.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 2112211981 - 2⁵ = 2112211949 is a prime.

It is a super-2 number, since 2×2112211981² = 8922878905359888722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2112211951) 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, 96009625 + ... + 96009646.

It is an arithmetic number, because the mean of its divisors is an integer number (576057816).

Almost surely, 2^2112211981 is an apocalyptic number.

It is an amenable number.

2112211981 is a deficient number, since it is larger than the sum of its proper divisors (192019283).

2112211981 is a wasteful number, since it uses less digits than its factorization.

2112211981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 192019282.

The product of its digits is 576, while the sum is 28.

The square root of 2112211981 is about 45958.8074366601. The cubic root of 2112211981 is about 1283.0566558359.

The spelling of 2112211981 in words is "two billion, one hundred twelve million, two hundred eleven thousand, nine hundred eighty-one".