8217401721 has 8 divisors (see below), whose sum is σ = 10957254624. Its totient is φ = 5477908320.

The previous prime is 8217401719. The next prime is 8217401737. The reversal of 8217401721 is 1271047128.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 8217401721 - 2¹ = 8217401719 is a prime.

It is not an unprimeable number, because it can be changed into a prime (8217401771) 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, 31036 + ... + 131901.

It is an arithmetic number, because the mean of its divisors is an integer number (1369656828).

Almost surely, 2^8217401721 is an apocalyptic number.

It is an amenable number.

8217401721 is a deficient number, since it is larger than the sum of its proper divisors (2739852903).

8217401721 is a wasteful number, since it uses less digits than its factorization.

8217401721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 179751.

The product of its (nonzero) digits is 6272, while the sum is 33.

The square root of 8217401721 is about 90649.8853887858. The cubic root of 8217401721 is about 2017.9551342848.

Adding to 8217401721 its reverse (1271047128), we get a palindrome (9488448849).

The spelling of 8217401721 in words is "eight billion, two hundred seventeen million, four hundred one thousand, seven hundred twenty-one".