2102491 has 4 divisors (see below), whose sum is σ = 2105392. Its totient is φ = 2099592.

The previous prime is 2102489. The next prime is 2102497. The reversal of 2102491 is 1942012.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 2102491 - 2¹ = 2102489 is a prime.

It is an Ulam number.

It is a d-powerful number, because it can be written as 2⁹ + 1 + 0 + 2²¹ + 4⁶ + 9³ + 1 .

It is a Duffinian number.

2102491 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (2102497) 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, 721 + ... + 2173.

It is an arithmetic number, because the mean of its divisors is an integer number (526348).

2^2102491 is an apocalyptic number.

2102491 is a deficient number, since it is larger than the sum of its proper divisors (2901).

2102491 is a wasteful number, since it uses less digits than its factorization.

2102491 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2900.

The product of its (nonzero) digits is 144, while the sum is 19.

The square root of 2102491 is about 1449.9968965484. The cubic root of 2102491 is about 128.1085301852.

It can be divided in two parts, 21024 and 91, that added together give a triangular number (21115 = T₂₀₅).

The spelling of 2102491 in words is "two million, one hundred two thousand, four hundred ninety-one".