1641891 has 8 divisors (see below), whose sum is σ = 2199744. Its totient is φ = 1089320.

The previous prime is 1641889. The next prime is 1641907. The reversal of 1641891 is 1981461.

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 1641891 - 2¹ = 1641889 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1641811) 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, 525 + ... + 1886.

It is an arithmetic number, because the mean of its divisors is an integer number (274968).

2^1641891 is an apocalyptic number.

1641891 is a deficient number, since it is larger than the sum of its proper divisors (557853).

1641891 is a wasteful number, since it uses less digits than its factorization.

1641891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2641.

The product of its digits is 1728, while the sum is 30.

The square root of 1641891 is about 1281.3629462412. The cubic root of 1641891 is about 117.9726787268.

The spelling of 1641891 in words is "one million, six hundred forty-one thousand, eight hundred ninety-one".