2120991 has 16 divisors (see below), whose sum is σ = 3006720. Its totient is φ = 1327040.

The previous prime is 2120981. The next prime is 2121011. The reversal of 2120991 is 1990212.

2120991 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a cyclic number.

It is not a de Polignac number, because 2120991 - 2⁷ = 2120863 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2120941) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3811 + ... + 4331.

It is an arithmetic number, because the mean of its divisors is an integer number (187920).

2^2120991 is an apocalyptic number.

2120991 is a deficient number, since it is larger than the sum of its proper divisors (885729).

2120991 is a wasteful number, since it uses less digits than its factorization.

2120991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 606.

The product of its (nonzero) digits is 324, while the sum is 24.

The square root of 2120991 is about 1456.3622488928. The cubic root of 2120991 is about 128.4831794766.

It can be divided in two parts, 21 and 20991, that added together give a palindrome (21012).

The spelling of 2120991 in words is "two million, one hundred twenty thousand, nine hundred ninety-one".