1242215553 has 4 divisors (see below), whose sum is σ = 1656287408. Its totient is φ = 828143700.

The previous prime is 1242215549. The next prime is 1242215561. The reversal of 1242215553 is 3555122421.

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.

It is not a de Polignac number, because 1242215553 - 2² = 1242215549 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1242215553.

It is not an unprimeable number, because it can be changed into a prime (1242215563) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 207035923 + ... + 207035928.

It is an arithmetic number, because the mean of its divisors is an integer number (414071852).

Almost surely, 2^1242215553 is an apocalyptic number.

It is an amenable number.

1242215553 is a deficient number, since it is larger than the sum of its proper divisors (414071855).

1242215553 is an equidigital number, since it uses as much as digits as its factorization.

1242215553 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 414071854.

The product of its digits is 12000, while the sum is 30.

The square root of 1242215553 is about 35245.0784223840. The cubic root of 1242215553 is about 1074.9765426286.

Adding to 1242215553 its reverse (3555122421), we get a palindrome (4797337974).

The spelling of 1242215553 in words is "one billion, two hundred forty-two million, two hundred fifteen thousand, five hundred fifty-three".