1226566656221 has 8 divisors (see below), whose sum is σ = 1227752092320. Its totient is φ = 1225381378608.

The previous prime is 1226566656167. The next prime is 1226566656229.

1226566656221 is nontrivially palindromic in base 10.

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 1226566656221 - 2¹⁸ = 1226566394077 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1226566656221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1226566656229) 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, 20499470 + ... + 20559216.

It is an arithmetic number, because the mean of its divisors is an integer number (153469011540).

Almost surely, 2^{1226566656221} is an apocalyptic number.

It is an amenable number.

1226566656221 is a deficient number, since it is larger than the sum of its proper divisors (1185436099).

1226566656221 is a wasteful number, since it uses less digits than its factorization.

1226566656221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 79243.

The product of its digits is 3110400, while the sum is 50.

The spelling of 1226566656221 in words is "one trillion, two hundred twenty-six billion, five hundred sixty-six million, six hundred fifty-six thousand, two hundred twenty-one".