1216221753505 has 8 divisors (see below), whose sum is σ = 1592144841024. Its totient is φ = 884524911600.

The previous prime is 1216221753493. The next prime is 1216221753517. The reversal of 1216221753505 is 5053571226121.

It is an interprime number because it is at equal distance from previous prime (1216221753493) and next prime (1216221753517).

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

It is not a de Polignac number, because 1216221753505 - 2¹³ = 1216221745313 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11056561341 + ... + 11056561450.

It is an arithmetic number, because the mean of its divisors is an integer number (199018105128).

Almost surely, 2^{1216221753505} is an apocalyptic number.

It is an amenable number.

1216221753505 is a deficient number, since it is larger than the sum of its proper divisors (375923087519).

1216221753505 is a wasteful number, since it uses less digits than its factorization.

1216221753505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22113122807.

The product of its (nonzero) digits is 126000, while the sum is 40.

Adding to 1216221753505 its reverse (5053571226121), we get a palindrome (6269792979626).

The spelling of 1216221753505 in words is "one trillion, two hundred sixteen billion, two hundred twenty-one million, seven hundred fifty-three thousand, five hundred five".