1221502243 has 16 divisors (see below), whose sum is σ = 1367815680. Its totient is φ = 1083067776.

The previous prime is 1221502237. The next prime is 1221502291. The reversal of 1221502243 is 3422051221.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 1221502243 - 2²¹ = 1219405091 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1221502543) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 66046 + ... + 82492.

It is an arithmetic number, because the mean of its divisors is an integer number (85488480).

Almost surely, 2^1221502243 is an apocalyptic number.

1221502243 is a gapful number since it is divisible by the number (13) formed by its first and last digit.

1221502243 is a deficient number, since it is larger than the sum of its proper divisors (146313437).

1221502243 is a wasteful number, since it uses less digits than its factorization.

1221502243 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16686.

The product of its (nonzero) digits is 960, while the sum is 22.

The square root of 1221502243 is about 34949.9963233188. The cubic root of 1221502243 is about 1068.9681271185.

Adding to 1221502243 its reverse (3422051221), we get a palindrome (4643553464).

The spelling of 1221502243 in words is "one billion, two hundred twenty-one million, five hundred two thousand, two hundred forty-three".