1242170561 has 2 divisors, whose sum is σ = 1242170562. Its totient is φ = 1242170560.

The previous prime is 1242170557. The next prime is 1242170639. The reversal of 1242170561 is 1650712421.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1105163536 + 137007025 = 33244^2 + 11705^2 .

It is an emirp because it is prime and its reverse (1650712421) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1242170561 - 2² = 1242170557 is a prime.

It is not a weakly prime, because it can be changed into another prime (1242170551) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 621085280 + 621085281.

It is an arithmetic number, because the mean of its divisors is an integer number (621085281).

Almost surely, 2^1242170561 is an apocalyptic number.

It is an amenable number.

1242170561 is a deficient number, since it is larger than the sum of its proper divisors (1).

1242170561 is an equidigital number, since it uses as much as digits as its factorization.

1242170561 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3360, while the sum is 29.

The square root of 1242170561 is about 35244.4401430921. The cubic root of 1242170561 is about 1074.9635642239.

Adding to 1242170561 its reverse (1650712421), we get a palindrome (2892882982).

The spelling of 1242170561 in words is "one billion, two hundred forty-two million, one hundred seventy thousand, five hundred sixty-one".