2091921 has 8 divisors (see below), whose sum is σ = 3003840. Its totient is φ = 1287312.

The previous prime is 2091917. The next prime is 2091931. The reversal of 2091921 is 1291902.

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

It is not a de Polignac number, because 2091921 - 2² = 2091917 is a prime.

It is a super-2 number, since 2×2091921² = 8752266940482, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 2091891 and 2091900.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2091931) 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, 26781 + ... + 26858.

It is an arithmetic number, because the mean of its divisors is an integer number (375480).

2^2091921 is an apocalyptic number.

It is an amenable number.

2091921 is a deficient number, since it is larger than the sum of its proper divisors (911919).

2091921 is a wasteful number, since it uses less digits than its factorization.

2091921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53655.

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

The square root of 2091921 is about 1446.3474686257. The cubic root of 2091921 is about 127.8934864232.

The spelling of 2091921 in words is "two million, ninety-one thousand, nine hundred twenty-one".