1668401 has 12 divisors (see below), whose sum is σ = 1969920. Its totient is φ = 1408680.

The previous prime is 1668379. The next prime is 1668427. The reversal of 1668401 is 1048661.

It is a de Polignac number, because none of the positive numbers 2^k-1668401 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1668481) 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 11 ways as a sum of consecutive naturals, for example, 3656 + ... + 4086.

It is an arithmetic number, because the mean of its divisors is an integer number (164160).

2^1668401 is an apocalyptic number.

It is an amenable number.

1668401 is a deficient number, since it is larger than the sum of its proper divisors (301519).

1668401 is an equidigital number, since it uses as much as digits as its factorization.

1668401 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 524 (or 517 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 26.

The square root of 1668401 is about 1291.6659784944. The cubic root of 1668401 is about 118.6042214836.

The spelling of 1668401 in words is "one million, six hundred sixty-eight thousand, four hundred one".