1242120013 has 4 divisors (see below), whose sum is σ = 1243566880. Its totient is φ = 1240673148.

The previous prime is 1242120001. The next prime is 1242120023. The reversal of 1242120013 is 3100212421.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 3100212421 = 27031 ⋅114691.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1242120013 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1242120023) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 722145 + ... + 723862.

It is an arithmetic number, because the mean of its divisors is an integer number (310891720).

Almost surely, 2^1242120013 is an apocalyptic number.

It is an amenable number.

1242120013 is a deficient number, since it is larger than the sum of its proper divisors (1446867).

1242120013 is an equidigital number, since it uses as much as digits as its factorization.

1242120013 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1446866.

The product of its (nonzero) digits is 96, while the sum is 16.

The square root of 1242120013 is about 35243.7230297822. The cubic root of 1242120013 is about 1074.9489827600.

Adding to 1242120013 its reverse (3100212421), we get a palindrome (4342332434).

The spelling of 1242120013 in words is "one billion, two hundred forty-two million, one hundred twenty thousand, thirteen".