1217660221 has 8 divisors (see below), whose sum is σ = 1235326400. Its totient is φ = 1200020832.

The previous prime is 1217660219. The next prime is 1217660233. The reversal of 1217660221 is 1220667121.

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 1217660221 - 2¹ = 1217660219 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 1217660221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1217660251) 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, 96166 + ... + 108088.

It is an arithmetic number, because the mean of its divisors is an integer number (154415800).

Almost surely, 2^1217660221 is an apocalyptic number.

It is an amenable number.

1217660221 is a deficient number, since it is larger than the sum of its proper divisors (17666179).

1217660221 is a wasteful number, since it uses less digits than its factorization.

1217660221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13395.

The product of its (nonzero) digits is 2016, while the sum is 28.

The square root of 1217660221 is about 34894.9884797230. The cubic root of 1217660221 is about 1067.8461991606.

The spelling of 1217660221 in words is "one billion, two hundred seventeen million, six hundred sixty thousand, two hundred twenty-one".