1221727656245 has 8 divisors (see below), whose sum is σ = 1505696787384. Its totient is φ = 950966391744.

The previous prime is 1221727656217. The next prime is 1221727656283. The reversal of 1221727656245 is 5426567271221.

It can be written as a sum of positive squares in 4 ways, for example, as 627362211844 + 594365444401 = 792062^2 + 770951^2 .

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 1221727656245 - 2¹² = 1221727652149 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 1221727656193 and 1221727656202.

It is a congruent 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, 3301966454 + ... + 3301966823.

It is an arithmetic number, because the mean of its divisors is an integer number (188212098423).

Almost surely, 2^{1221727656245} is an apocalyptic number.

It is an amenable number.

1221727656245 is a deficient number, since it is larger than the sum of its proper divisors (283969131139).

1221727656245 is an equidigital number, since it uses as much as digits as its factorization.

1221727656245 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6603933319.

The product of its digits is 2822400, while the sum is 50.

The spelling of 1221727656245 in words is "one trillion, two hundred twenty-one billion, seven hundred twenty-seven million, six hundred fifty-six thousand, two hundred forty-five".