1221003213 has 16 divisors (see below), whose sum is σ = 1723276800. Its totient is φ = 766845360.

The previous prime is 1221003209. The next prime is 1221003227. The reversal of 1221003213 is 3123001221.

It is not a de Polignac number, because 1221003213 - 2² = 1221003209 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1221003192 and 1221003201.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221003233) 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, 49633 + ... + 70038.

It is an arithmetic number, because the mean of its divisors is an integer number (107704800).

Almost surely, 2^1221003213 is an apocalyptic number.

It is an amenable number.

1221003213 is a deficient number, since it is larger than the sum of its proper divisors (502273587).

1221003213 is a wasteful number, since it uses less digits than its factorization.

1221003213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 119872.

The product of its (nonzero) digits is 72, while the sum is 15.

The square root of 1221003213 is about 34942.8563944049. The cubic root of 1221003213 is about 1068.8225359476.

Adding to 1221003213 its reverse (3123001221), we get a palindrome (4344004434).

The spelling of 1221003213 in words is "one billion, two hundred twenty-one million, three thousand, two hundred thirteen".