1221243415 has 12 divisors (see below), whose sum is σ = 1704756456. Its totient is φ = 837423888.

The previous prime is 1221243391. The next prime is 1221243427. The reversal of 1221243415 is 5143421221.

It is not a de Polignac number, because 1221243415 - 2⁹ = 1221242903 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1221243415.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2492089 + ... + 2492578.

It is an arithmetic number, because the mean of its divisors is an integer number (142063038).

Almost surely, 2^1221243415 is an apocalyptic number.

1221243415 is a deficient number, since it is larger than the sum of its proper divisors (483513041).

1221243415 is an equidigital number, since it uses as much as digits as its factorization.

1221243415 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4984686 (or 4984679 counting only the distinct ones).

The product of its digits is 1920, while the sum is 25.

The square root of 1221243415 is about 34946.2932941392. The cubic root of 1221243415 is about 1068.8926194315.

Adding to 1221243415 its reverse (5143421221), we get a palindrome (6364664636).

The spelling of 1221243415 in words is "one billion, two hundred twenty-one million, two hundred forty-three thousand, four hundred fifteen".