1242155211 has 32 divisors (see below), whose sum is σ = 1823712000. Its totient is φ = 745804800.

The previous prime is 1242155207. The next prime is 1242155219. The reversal of 1242155211 is 1125512421.

It is a happy number.

It is not a de Polignac number, because 1242155211 - 2² = 1242155207 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1242155219) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2489040 + ... + 2489538.

It is an arithmetic number, because the mean of its divisors is an integer number (56991000).

Almost surely, 2^1242155211 is an apocalyptic number.

1242155211 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

1242155211 is a deficient number, since it is larger than the sum of its proper divisors (581556789).

1242155211 is a wasteful number, since it uses less digits than its factorization.

1242155211 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1067.

The product of its digits is 800, while the sum is 24.

The square root of 1242155211 is about 35244.2223775756. Note that the first 3 decimals coincide. The cubic root of 1242155211 is about 1074.9591362870.

Adding to 1242155211 its reverse (1125512421), we get a palindrome (2367667632).

The spelling of 1242155211 in words is "one billion, two hundred forty-two million, one hundred fifty-five thousand, two hundred eleven".