8417721 has 12 divisors (see below), whose sum is σ = 12154128. Its totient is φ = 5179824.

The previous prime is 8417719. The next prime is 8417729. The reversal of 8417721 is 1277148.

It is not a de Polignac number, because 8417721 - 2¹ = 8417719 is a prime.

It is not an unprimeable number, because it can be changed into a prime (8417729) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 7795 + ... + 8808.

It is an arithmetic number, because the mean of its divisors is an integer number (1012844).

Almost surely, 2^8417721 is an apocalyptic number.

It is an amenable number.

8417721 is a deficient number, since it is larger than the sum of its proper divisors (3736407).

8417721 is a wasteful number, since it uses less digits than its factorization.

8417721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16632 (or 16619 counting only the distinct ones).

The product of its digits is 3136, while the sum is 30.

The square root of 8417721 is about 2901.3309015002. The cubic root of 8417721 is about 203.4221198445.

The spelling of 8417721 in words is "eight million, four hundred seventeen thousand, seven hundred twenty-one".