8851721 has 2 divisors, whose sum is σ = 8851722. Its totient is φ = 8851720.

The previous prime is 8851697. The next prime is 8851723. The reversal of 8851721 is 1271588.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 6175225 + 2676496 = 2485^2 + 1636^2 .

It is a cyclic number.

It is not a de Polignac number, because 8851721 - 2⁶ = 8851657 is a prime.

Together with 8851723, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (8851723) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4425860 + 4425861.

It is an arithmetic number, because the mean of its divisors is an integer number (4425861).

Almost surely, 2^8851721 is an apocalyptic number.

It is an amenable number.

8851721 is a deficient number, since it is larger than the sum of its proper divisors (1).

8851721 is an equidigital number, since it uses as much as digits as its factorization.

8851721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4480, while the sum is 32.

The square root of 8851721 is about 2975.1841959785. The cubic root of 8851721 is about 206.8597071903.

The spelling of 8851721 in words is "eight million, eight hundred fifty-one thousand, seven hundred twenty-one".