8417928721 has 2 divisors, whose sum is σ = 8417928722. Its totient is φ = 8417928720.

The previous prime is 8417928703. The next prime is 8417928731. The reversal of 8417928721 is 1278297148.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 5209952400 + 3207976321 = 72180^2 + 56639^2 .

It is a cyclic number.

It is not a de Polignac number, because 8417928721 - 2¹³ = 8417920529 is a prime.

It is not a weakly prime, because it can be changed into another prime (8417928731) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4208964360 + 4208964361.

It is an arithmetic number, because the mean of its divisors is an integer number (4208964361).

Almost surely, 2^8417928721 is an apocalyptic number.

It is an amenable number.

8417928721 is a deficient number, since it is larger than the sum of its proper divisors (1).

8417928721 is an equidigital number, since it uses as much as digits as its factorization.

8417928721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 451584, while the sum is 49.

The square root of 8417928721 is about 91749.2709562316. The cubic root of 8417928721 is about 2034.2379308834.

The spelling of 8417928721 in words is "eight billion, four hundred seventeen million, nine hundred twenty-eight thousand, seven hundred twenty-one".