1017721 has 2 divisors, whose sum is σ = 1017722. Its totient is φ = 1017720.

The previous prime is 1017719. The next prime is 1017749. The reversal of 1017721 is 1277101.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 657721 + 360000 = 811^2 + 600^2 .

It is a cyclic number.

It is not a de Polignac number, because 1017721 - 2¹ = 1017719 is a prime.

Together with 1017719, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (1017781) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 508860 + 508861.

It is an arithmetic number, because the mean of its divisors is an integer number (508861).

2^1017721 is an apocalyptic number.

It is an amenable number.

1017721 is a deficient number, since it is larger than the sum of its proper divisors (1).

1017721 is an equidigital number, since it uses as much as digits as its factorization.

1017721 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 98, while the sum is 19.

The square root of 1017721 is about 1008.8215897769. The cubic root of 1017721 is about 100.5872446863.

The spelling of 1017721 in words is "one million, seventeen thousand, seven hundred twenty-one".