2105691 has 8 divisors (see below), whose sum is σ = 3208704. Its totient is φ = 1203240.

The previous prime is 2105681. The next prime is 2105693. The reversal of 2105691 is 1965012.

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

It is not a de Polignac number, because 2105691 - 2¹³ = 2097499 is a prime.

2105691 is a modest number, since divided by 5691 gives 21 as remainder.

2105691 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (2105693) 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, 50115 + ... + 50156.

It is an arithmetic number, because the mean of its divisors is an integer number (401088).

2^2105691 is an apocalyptic number.

2105691 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

2105691 is a deficient number, since it is larger than the sum of its proper divisors (1103013).

2105691 is a wasteful number, since it uses less digits than its factorization.

2105691 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 100281.

The product of its (nonzero) digits is 540, while the sum is 24.

The square root of 2105691 is about 1451.0999276411. The cubic root of 2105691 is about 128.1734911437.

The spelling of 2105691 in words is "two million, one hundred five thousand, six hundred ninety-one".