2112031991 has 4 divisors (see below), whose sum is σ = 2113511400. Its totient is φ = 2110552584.

The previous prime is 2112031967. The next prime is 2112031993. The reversal of 2112031991 is 1991302112.

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

It is a cyclic number.

It is not a de Polignac number, because 2112031991 - 2¹⁰ = 2112030967 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2112031993) 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, 737561 + ... + 740418.

It is an arithmetic number, because the mean of its divisors is an integer number (528377850).

Almost surely, 2^2112031991 is an apocalyptic number.

2112031991 is a deficient number, since it is larger than the sum of its proper divisors (1479409).

2112031991 is a wasteful number, since it uses less digits than its factorization.

2112031991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1479408.

The product of its (nonzero) digits is 972, while the sum is 29.

The square root of 2112031991 is about 45956.8492283794. The cubic root of 2112031991 is about 1283.0202100105.

The spelling of 2112031991 in words is "two billion, one hundred twelve million, thirty-one thousand, nine hundred ninety-one".