1221267042 has 18 divisors (see below), whose sum is σ = 2646399873. Its totient is φ = 407039592.

The previous prime is 1221267017. The next prime is 1221267067. The reversal of 1221267042 is 2407621221.

It is an interprime number because it is at equal distance from previous prime (1221267017) and next prime (1221267067).

It can be written as a sum of positive squares in 2 ways, for example, as 1199167641 + 22099401 = 34629^2 + 4701^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=24711.

It is a junction number, because it is equal to n+sod(n) for n = 1221266997 and 1221267015.

It is an unprimeable number.

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 8 ways as a sum of consecutive naturals, for example, 144148 + ... + 152384.

Almost surely, 2^1221267042 is an apocalyptic number.

1221267042 is an abundant number, since it is smaller than the sum of its proper divisors (1425132831).

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

1221267042 is an frugal number, since it uses more digits than its factorization.

1221267042 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16482 (or 8242 counting only the distinct ones).

The product of its (nonzero) digits is 2688, while the sum is 27.

The square root of 1221267042 is about 34946.6313398016. The cubic root of 1221267042 is about 1068.8995125600.

Adding to 1221267042 its reverse (2407621221), we get a palindrome (3628888263).

The spelling of 1221267042 in words is "one billion, two hundred twenty-one million, two hundred sixty-seven thousand, forty-two".