1242155455 has 4 divisors (see below), whose sum is σ = 1490586552. Its totient is φ = 993724360.

The previous prime is 1242155449. The next prime is 1242155477. The reversal of 1242155455 is 5545512421.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 1242155455 - 2⁵ = 1242155423 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 1242155455.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 124215541 + ... + 124215550.

It is an arithmetic number, because the mean of its divisors is an integer number (372646638).

Almost surely, 2^1242155455 is an apocalyptic number.

1242155455 is a deficient number, since it is larger than the sum of its proper divisors (248431097).

1242155455 is an equidigital number, since it uses as much as digits as its factorization.

1242155455 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 248431096.

The product of its digits is 40000, while the sum is 34.

The square root of 1242155455 is about 35244.2258391357. The cubic root of 1242155455 is about 1074.9592066727.

Adding to 1242155455 its reverse (5545512421), we get a palindrome (6787667876).

It can be divided in two parts, 12421 and 55455, that added together give a palindrome (67876).

The spelling of 1242155455 in words is "one billion, two hundred forty-two million, one hundred fifty-five thousand, four hundred fifty-five".