1221247042 has 16 divisors (see below), whose sum is σ = 1877797152. Its totient is φ = 595365120.

The previous prime is 1221246997. The next prime is 1221247051. The reversal of 1221247042 is 2407421221.

It is a junction number, because it is equal to n+sod(n) for n = 1221246998 and 1221247016.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 37317 + ... + 61927.

It is an arithmetic number, because the mean of its divisors is an integer number (117362322).

Almost surely, 2^1221247042 is an apocalyptic number.

1221247042 is a deficient number, since it is larger than the sum of its proper divisors (656550110).

1221247042 is a wasteful number, since it uses less digits than its factorization.

1221247042 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25233.

The product of its (nonzero) digits is 1792, while the sum is 25.

The square root of 1221247042 is about 34946.3451880164. The cubic root of 1221247042 is about 1068.8936776071.

Adding to 1221247042 its reverse (2407421221), we get a palindrome (3628668263).

The spelling of 1221247042 in words is "one billion, two hundred twenty-one million, two hundred forty-seven thousand, forty-two".