1668681 has 32 divisors (see below), whose sum is σ = 2886400. Its totient is φ = 944784.

The previous prime is 1668679. The next prime is 1668683. The reversal of 1668681 is 1868661.

It is an interprime number because it is at equal distance from previous prime (1668679) and next prime (1668683).

It is not a de Polignac number, because 1668681 - 2¹ = 1668679 is a prime.

It is a super-2 number, since 2×1668681² = 5568992559522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1668683) 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 31 ways as a sum of consecutive naturals, for example, 15255 + ... + 15363.

It is an arithmetic number, because the mean of its divisors is an integer number (90200).

2^1668681 is an apocalyptic number.

It is an amenable number.

1668681 is a deficient number, since it is larger than the sum of its proper divisors (1217719).

1668681 is an frugal number, since it uses more digits than its factorization.

1668681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 137 (or 119 counting only the distinct ones).

The product of its digits is 13824, while the sum is 36.

The square root of 1668681 is about 1291.7743611018. The cubic root of 1668681 is about 118.6108560446.

The spelling of 1668681 in words is "one million, six hundred sixty-eight thousand, six hundred eighty-one".