1242123140 has 12 divisors (see below), whose sum is σ = 2608458636. Its totient is φ = 496849248.

The previous prime is 1242123109. The next prime is 1242123143. The reversal of 1242123140 is 413212421.

It can be written as a sum of positive squares in 2 ways, for example, as 617423104 + 624700036 = 24848^2 + 24994^2 .

It is a Harshad number since it is a multiple of its sum of digits (20), and also a Moran number because the ratio is a prime number: 62106157 = 1242123140 / (1 + 2 + 4 + 2 + 1 + 2 + 3 + 1 + 4 + 0).

It is not an unprimeable number, because it can be changed into a prime (1242123143) 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, 31053059 + ... + 31053098.

It is an arithmetic number, because the mean of its divisors is an integer number (217371553).

Almost surely, 2^1242123140 is an apocalyptic number.

1242123140 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1242123140 is an abundant number, since it is smaller than the sum of its proper divisors (1366335496).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1242123140 is a wasteful number, since it uses less digits than its factorization.

1242123140 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 62106166 (or 62106164 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 20.

The square root of 1242123140 is about 35243.7673922638. The cubic root of 1242123140 is about 1074.9498848099.

Adding to 1242123140 its reverse (413212421), we get a palindrome (1655335561).

The spelling of 1242123140 in words is "one billion, two hundred forty-two million, one hundred twenty-three thousand, one hundred forty".