8378621 has 2 divisors, whose sum is σ = 8378622. Its totient is φ = 8378620.

The previous prime is 8378581. The next prime is 8378633. The reversal of 8378621 is 1268738.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 6446521 + 1932100 = 2539^2 + 1390^2 .

It is a cyclic number.

It is not a de Polignac number, because 8378621 - 2¹⁰ = 8377597 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (8378641) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4189310 + 4189311.

It is an arithmetic number, because the mean of its divisors is an integer number (4189311).

Almost surely, 2^8378621 is an apocalyptic number.

It is an amenable number.

8378621 is a deficient number, since it is larger than the sum of its proper divisors (1).

8378621 is an equidigital number, since it uses as much as digits as its factorization.

8378621 is an evil number, because the sum of its binary digits is even.

The product of its digits is 16128, while the sum is 35.

The square root of 8378621 is about 2894.5847716037. The cubic root of 8378621 is about 203.1066681997.

The spelling of 8378621 in words is "eight million, three hundred seventy-eight thousand, six hundred twenty-one".