1217290221 has 32 divisors (see below), whose sum is σ = 2073415680. Its totient is φ = 691411248.

The previous prime is 1217290213. The next prime is 1217290229. The reversal of 1217290221 is 1220927121.

It is an interprime number because it is at equal distance from previous prime (1217290213) and next prime (1217290229).

It is not a de Polignac number, because 1217290221 - 2³ = 1217290213 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 (1217290229) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 12280 + ... + 50846.

It is an arithmetic number, because the mean of its divisors is an integer number (64794240).

Almost surely, 2^1217290221 is an apocalyptic number.

It is an amenable number.

1217290221 is a deficient number, since it is larger than the sum of its proper divisors (856125459).

1217290221 is a wasteful number, since it uses less digits than its factorization.

1217290221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38750 (or 38744 counting only the distinct ones).

The product of its (nonzero) digits is 1008, while the sum is 27.

The square root of 1217290221 is about 34889.6864560288. The cubic root of 1217290221 is about 1067.7380291055.

The spelling of 1217290221 in words is "one billion, two hundred seventeen million, two hundred ninety thousand, two hundred twenty-one".