1644091 has 4 divisors (see below), whose sum is σ = 1646800. Its totient is φ = 1641384.

The previous prime is 1644079. The next prime is 1644103. The reversal of 1644091 is 1904461.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (1644079) and next prime (1644103).

It is a cyclic number.

It is not a de Polignac number, because 1644091 - 2⁷ = 1643963 is a prime.

It is a super-3 number, since 3×1644091³ = 13332107615311936713, which contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1644001) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 25 + ... + 1813.

It is an arithmetic number, because the mean of its divisors is an integer number (411700).

2^1644091 is an apocalyptic number.

1644091 is a deficient number, since it is larger than the sum of its proper divisors (2709).

1644091 is an equidigital number, since it uses as much as digits as its factorization.

1644091 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2708.

The product of its (nonzero) digits is 864, while the sum is 25.

The square root of 1644091 is about 1282.2211197761. The cubic root of 1644091 is about 118.0253464655.

The spelling of 1644091 in words is "one million, six hundred forty-four thousand, ninety-one".