1242366561 has 24 divisors (see below), whose sum is σ = 1820000000. Its totient is φ = 816521472.

The previous prime is 1242366497. The next prime is 1242366569. The reversal of 1242366561 is 1656632421.

1242366561 is a `hidden beast` number, since 1 + 242 + 366 + 56 + 1 = 666.

It is not a de Polignac number, because 1242366561 - 2⁶ = 1242366497 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1242366569) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 887340 + ... + 888738.

Almost surely, 2^1242366561 is an apocalyptic number.

It is an amenable number.

1242366561 is a deficient number, since it is larger than the sum of its proper divisors (577633439).

1242366561 is a wasteful number, since it uses less digits than its factorization.

1242366561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2733 (or 2730 counting only the distinct ones).

The product of its digits is 51840, while the sum is 36.

The square root of 1242366561 is about 35247.2206138300. The cubic root of 1242366561 is about 1075.0201001470.

Adding to 1242366561 its reverse (1656632421), we get a palindrome (2898998982).

The spelling of 1242366561 in words is "one billion, two hundred forty-two million, three hundred sixty-six thousand, five hundred sixty-one".