1021701661 has 2 divisors, whose sum is σ = 1021701662. Its totient is φ = 1021701660.

The previous prime is 1021701623. The next prime is 1021701677. The reversal of 1021701661 is 1661071201.

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., 969139161 + 52562500 = 31131^2 + 7250^2 .

It is a cyclic number.

It is not a de Polignac number, because 1021701661 - 2⁷ = 1021701533 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1021701601) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 510850830 + 510850831.

It is an arithmetic number, because the mean of its divisors is an integer number (510850831).

Almost surely, 2^1021701661 is an apocalyptic number.

It is an amenable number.

1021701661 is a deficient number, since it is larger than the sum of its proper divisors (1).

1021701661 is an equidigital number, since it uses as much as digits as its factorization.

1021701661 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 504, while the sum is 25.

The square root of 1021701661 is about 31964.0682798670. The cubic root of 1021701661 is about 1007.1821797989.

Adding to 1021701661 its reverse (1661071201), we get a palindrome (2682772862).

The spelling of 1021701661 in words is "one billion, twenty-one million, seven hundred one thousand, six hundred sixty-one".