1661671 has 8 divisors (see below), whose sum is σ = 1875600. Its totient is φ = 1458240.

The previous prime is 1661669. The next prime is 1661677. The reversal of 1661671 is 1761661.

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 1661671 - 2¹ = 1661669 is a prime.

It is a super-2 number, since 2×1661671² = 5522301024482, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1661677) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2286 + ... + 2923.

It is an arithmetic number, because the mean of its divisors is an integer number (234450).

2^1661671 is an apocalyptic number.

1661671 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

1661671 is a deficient number, since it is larger than the sum of its proper divisors (213929).

1661671 is a wasteful number, since it uses less digits than its factorization.

1661671 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5249.

The product of its digits is 1512, while the sum is 28.

The square root of 1661671 is about 1289.0581833261. The cubic root of 1661671 is about 118.4445312390. Note that the first 3 decimals are identical.

It can be divided in two parts, 1661 and 671, that added together give a palindrome (2332).

The spelling of 1661671 in words is "one million, six hundred sixty-one thousand, six hundred seventy-one".