2217920321 has 4 divisors (see below), whose sum is σ = 2239453632. Its totient is φ = 2196387012.

The previous prime is 2217920303. The next prime is 2217920323. The reversal of 2217920321 is 1230297122.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1230297122 = 2 ⋅615148561.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2217920321 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2217920323) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10766501 + ... + 10766706.

It is an arithmetic number, because the mean of its divisors is an integer number (559863408).

Almost surely, 2^2217920321 is an apocalyptic number.

It is an amenable number.

2217920321 is a deficient number, since it is larger than the sum of its proper divisors (21533311).

2217920321 is a wasteful number, since it uses less digits than its factorization.

2217920321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21533310.

The product of its (nonzero) digits is 3024, while the sum is 29.

The square root of 2217920321 is about 47094.8014222377. The cubic root of 2217920321 is about 1304.1132677355.

The spelling of 2217920321 in words is "two billion, two hundred seventeen million, nine hundred twenty thousand, three hundred twenty-one".