1968721 has 2 divisors, whose sum is σ = 1968722. Its totient is φ = 1968720.

The previous prime is 1968691. The next prime is 1968739. The reversal of 1968721 is 1278691.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1718721 + 250000 = 1311^2 + 500^2 .

It is a cyclic number.

It is not a de Polignac number, because 1968721 - 2¹³ = 1960529 is a prime.

1968721 is a lucky number.

It is equal to p₁₄₆₇₇₉ and since 1968721 and 146779 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (1968751) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 984360 + 984361.

It is an arithmetic number, because the mean of its divisors is an integer number (984361).

2^1968721 is an apocalyptic number.

It is an amenable number.

1968721 is a deficient number, since it is larger than the sum of its proper divisors (1).

1968721 is an equidigital number, since it uses as much as digits as its factorization.

1968721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6048, while the sum is 34.

The square root of 1968721 is about 1403.1111859008. Note that the first 4 decimals coincide. The cubic root of 1968721 is about 125.3318329821.

The spelling of 1968721 in words is "one million, nine hundred sixty-eight thousand, seven hundred twenty-one".