856240621 has 2 divisors, whose sum is σ = 856240622. Its totient is φ = 856240620.

The previous prime is 856240607. The next prime is 856240633. The reversal of 856240621 is 126042658.

856240621 is digitally balanced in base 2, 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., 467164996 + 389075625 = 21614^2 + 19725^2 .

It is a cyclic number.

It is not a de Polignac number, because 856240621 - 2²¹ = 854143469 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (856240601) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 428120310 + 428120311.

It is an arithmetic number, because the mean of its divisors is an integer number (428120311).

Almost surely, 2^856240621 is an apocalyptic number.

It is an amenable number.

856240621 is a deficient number, since it is larger than the sum of its proper divisors (1).

856240621 is an equidigital number, since it uses as much as digits as its factorization.

856240621 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 23040, while the sum is 34.

The square root of 856240621 is about 29261.5895159508. The cubic root of 856240621 is about 949.5808385371.

The spelling of 856240621 in words is "eight hundred fifty-six million, two hundred forty thousand, six hundred twenty-one".