1242561163 has 4 divisors (see below), whose sum is σ = 1261106920. Its totient is φ = 1224015408.

The previous prime is 1242561157. The next prime is 1242561167. The reversal of 1242561163 is 3611652421.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 3611652421 = 13 ⋅277819417.

It is a cyclic number.

It is not a de Polignac number, because 1242561163 - 2²¹ = 1240464011 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1242561167) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9272778 + ... + 9272911.

It is an arithmetic number, because the mean of its divisors is an integer number (315276730).

Almost surely, 2^1242561163 is an apocalyptic number.

1242561163 is a deficient number, since it is larger than the sum of its proper divisors (18545757).

1242561163 is an equidigital number, since it uses as much as digits as its factorization.

1242561163 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18545756.

The product of its digits is 8640, while the sum is 31.

The square root of 1242561163 is about 35249.9810354559. The cubic root of 1242561163 is about 1075.0762269365.

The spelling of 1242561163 in words is "one billion, two hundred forty-two million, five hundred sixty-one thousand, one hundred sixty-three".