1668553 has 2 divisors, whose sum is σ = 1668554. Its totient is φ = 1668552.

The previous prime is 1668551. The next prime is 1668587. The reversal of 1668553 is 3558661.

It is an a-pointer prime, because the next prime (1668587) can be obtained adding 1668553 to its sum of digits (34).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1530169 + 138384 = 1237^2 + 372^2 .

It is a cyclic number.

It is not a de Polignac number, because 1668553 - 2¹ = 1668551 is a prime.

It is a super-2 number, since 2×1668553² = 5568138227618, which contains 22 as substring.

Together with 1668551, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (1668551) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 834276 + 834277.

It is an arithmetic number, because the mean of its divisors is an integer number (834277).

2^1668553 is an apocalyptic number.

It is an amenable number.

1668553 is a deficient number, since it is larger than the sum of its proper divisors (1).

1668553 is an equidigital number, since it uses as much as digits as its factorization.

1668553 is an evil number, because the sum of its binary digits is even.

The product of its digits is 21600, while the sum is 34.

The square root of 1668553 is about 1291.7248158954. The cubic root of 1668553 is about 118.6078231945.

The spelling of 1668553 in words is "one million, six hundred sixty-eight thousand, five hundred fifty-three".