8370721 has 2 divisors, whose sum is σ = 8370722. Its totient is φ = 8370720.

The previous prime is 8370679. The next prime is 8370757. The reversal of 8370721 is 1270738.

It is a happy number.

8370721 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 7639696 + 731025 = 2764^2 + 855^2 .

It is a cyclic number.

It is not a de Polignac number, because 8370721 - 2²¹ = 6273569 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 8370721.

It is not a weakly prime, because it can be changed into another prime (8370521) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4185360 + 4185361.

It is an arithmetic number, because the mean of its divisors is an integer number (4185361).

Almost surely, 2^8370721 is an apocalyptic number.

It is an amenable number.

8370721 is a deficient number, since it is larger than the sum of its proper divisors (1).

8370721 is an equidigital number, since it uses as much as digits as its factorization.

8370721 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2352, while the sum is 28.

The square root of 8370721 is about 2893.2198326432. The cubic root of 8370721 is about 203.0428133307.

The spelling of 8370721 in words is "eight million, three hundred seventy thousand, seven hundred twenty-one".