1662121 has 2 divisors, whose sum is σ = 1662122. Its totient is φ = 1662120.

The previous prime is 1662119. The next prime is 1662149. The reversal of 1662121 is 1212661.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1022121 + 640000 = 1011^2 + 800^2 .

It is a cyclic number.

It is not a de Polignac number, because 1662121 - 2¹ = 1662119 is a prime.

Together with 1662119, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (1662161) 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 as a sum of consecutive naturals, namely, 831060 + 831061.

It is an arithmetic number, because the mean of its divisors is an integer number (831061).

2^1662121 is an apocalyptic number.

It is an amenable number.

1662121 is a deficient number, since it is larger than the sum of its proper divisors (1).

1662121 is an equidigital number, since it uses as much as digits as its factorization.

1662121 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 144, while the sum is 19.

The square root of 1662121 is about 1289.2327175495. The cubic root of 1662121 is about 118.4552223302.

Adding to 1662121 its reverse (1212661), we get a palindrome (2874782).

It can be divided in two parts, 1662 and 121, that multiplied together give a palindrome (201102).

The spelling of 1662121 in words is "one million, six hundred sixty-two thousand, one hundred twenty-one".