1242001561 has 8 divisors (see below), whose sum is σ = 1272757248. Its totient is φ = 1211268000.

The previous prime is 1242001559. The next prime is 1242001597. The reversal of 1242001561 is 1651002421.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1242001561 - 2¹ = 1242001559 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1242001361) 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 in 7 ways as a sum of consecutive naturals, for example, 211576 + ... + 217366.

It is an arithmetic number, because the mean of its divisors is an integer number (159094656).

Almost surely, 2^1242001561 is an apocalyptic number.

It is an amenable number.

1242001561 is a deficient number, since it is larger than the sum of its proper divisors (30755687).

1242001561 is an equidigital number, since it uses as much as digits as its factorization.

1242001561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11063.

The product of its (nonzero) digits is 480, while the sum is 22.

The square root of 1242001561 is about 35242.0425202626. The cubic root of 1242001561 is about 1074.9148116377.

Adding to 1242001561 its reverse (1651002421), we get a palindrome (2893003982).

The spelling of 1242001561 in words is "one billion, two hundred forty-two million, one thousand, five hundred sixty-one".