1671391 has 4 divisors (see below), whose sum is σ = 1675800. Its totient is φ = 1666984.

The previous prime is 1671379. The next prime is 1671421. The reversal of 1671391 is 1931761.

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

It is a cyclic number.

It is not a de Polignac number, because 1671391 - 2⁵ = 1671359 is a prime.

It is a Duffinian number.

1671391 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1671311) 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, 1576 + ... + 2413.

It is an arithmetic number, because the mean of its divisors is an integer number (418950).

2^1671391 is an apocalyptic number.

1671391 is a deficient number, since it is larger than the sum of its proper divisors (4409).

1671391 is an equidigital number, since it uses as much as digits as its factorization.

1671391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4408.

The product of its digits is 1134, while the sum is 28.

The square root of 1671391 is about 1292.8228803668. The cubic root of 1671391 is about 118.6750307968.

The spelling of 1671391 in words is "one million, six hundred seventy-one thousand, three hundred ninety-one".