1221213304 has 8 divisors (see below), whose sum is σ = 2289774960. Its totient is φ = 610606648.

The previous prime is 1221213293. The next prime is 1221213311. The reversal of 1221213304 is 4033121221.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (8).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 76325824 + ... + 76325839.

It is an arithmetic number, because the mean of its divisors is an integer number (286221870).

Almost surely, 2^1221213304 is an apocalyptic number.

It is an amenable number.

1221213304 is a deficient number, since it is larger than the sum of its proper divisors (1068561656).

1221213304 is a wasteful number, since it uses less digits than its factorization.

1221213304 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 152651669 (or 152651665 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 19.

The square root of 1221213304 is about 34945.8624732600. The cubic root of 1221213304 is about 1068.8838344807.

Adding to 1221213304 its reverse (4033121221), we get a palindrome (5254334525).

The spelling of 1221213304 in words is "one billion, two hundred twenty-one million, two hundred thirteen thousand, three hundred four".