1242616221 has 128 divisors (see below), whose sum is σ = 2388049920. Its totient is φ = 627756480.

The previous prime is 1242616213. The next prime is 1242616229. The reversal of 1242616221 is 1226162421.

1242616221 is a `hidden beast` number, since 1 + 2 + 42 + 616 + 2 + 2 + 1 = 666.

It is an interprime number because it is at equal distance from previous prime (1242616213) and next prime (1242616229).

It is not a de Polignac number, because 1242616221 - 2³ = 1242616213 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1242616229) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 7914675 + ... + 7914831.

It is an arithmetic number, because the mean of its divisors is an integer number (18656640).

Almost surely, 2^1242616221 is an apocalyptic number.

1242616221 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1242616221 is a deficient number, since it is larger than the sum of its proper divisors (1145433699).

1242616221 is an equidigital number, since it uses as much as digits as its factorization.

1242616221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 243 (or 225 counting only the distinct ones).

The product of its digits is 2304, while the sum is 27.

The square root of 1242616221 is about 35250.7619917641. The cubic root of 1242616221 is about 1075.0921056110.

Adding to 1242616221 its reverse (1226162421), we get a palindrome (2468778642).

The spelling of 1242616221 in words is "one billion, two hundred forty-two million, six hundred sixteen thousand, two hundred twenty-one".