1221243501 has 8 divisors (see below), whose sum is σ = 1724108544. Its totient is φ = 766270400.

The previous prime is 1221243479. The next prime is 1221243509. The reversal of 1221243501 is 1053421221.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1221243501 - 2⁵ = 1221243469 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221243509) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11972925 + ... + 11973026.

It is an arithmetic number, because the mean of its divisors is an integer number (215513568).

Almost surely, 2^1221243501 is an apocalyptic number.

It is an amenable number.

1221243501 is a deficient number, since it is larger than the sum of its proper divisors (502865043).

1221243501 is a wasteful number, since it uses less digits than its factorization.

1221243501 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23945971.

The product of its (nonzero) digits is 480, while the sum is 21.

The square root of 1221243501 is about 34946.2945245987. The cubic root of 1221243501 is about 1068.8926445220.

Adding to 1221243501 its reverse (1053421221), we get a palindrome (2274664722).

The spelling of 1221243501 in words is "one billion, two hundred twenty-one million, two hundred forty-three thousand, five hundred one".