1221212142 has 48 divisors (see below), whose sum is σ = 2716655760. Its totient is φ = 396240000.

The previous prime is 1221212089. The next prime is 1221212143. The reversal of 1221212142 is 2412121221.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221212143) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 374017 + ... + 377267.

It is an arithmetic number, because the mean of its divisors is an integer number (56596995).

Almost surely, 2^1221212142 is an apocalyptic number.

1221212142 is an abundant number, since it is smaller than the sum of its proper divisors (1495443618).

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

1221212142 is a wasteful number, since it uses less digits than its factorization.

1221212142 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3809 (or 3806 counting only the distinct ones).

The product of its digits is 128, while the sum is 18.

The square root of 1221212142 is about 34945.8458475396. The cubic root of 1221212142 is about 1068.8834954617.

Adding to 1221212142 its reverse (2412121221), we get a palindrome (3633333363).

The spelling of 1221212142 in words is "one billion, two hundred twenty-one million, two hundred twelve thousand, one hundred forty-two".