2091691 has 8 divisors (see below), whose sum is σ = 2516480. Its totient is φ = 1698408.

The previous prime is 2091671. The next prime is 2091703. The reversal of 2091691 is 1961902.

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

It is a cyclic number.

It is not a de Polignac number, because 2091691 - 2⁵ = 2091659 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2091631) 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, 7731 + ... + 7996.

It is an arithmetic number, because the mean of its divisors is an integer number (314560).

2^2091691 is an apocalyptic number.

2091691 is a deficient number, since it is larger than the sum of its proper divisors (424789).

2091691 is a wasteful number, since it uses less digits than its factorization.

2091691 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15753.

The product of its (nonzero) digits is 972, while the sum is 28.

The square root of 2091691 is about 1446.2679558090. The cubic root of 2091691 is about 127.8887990920. Note that the first 3 decimals are identical.

The spelling of 2091691 in words is "two million, ninety-one thousand, six hundred ninety-one".