856618541 has 2 divisors, whose sum is σ = 856618542. Its totient is φ = 856618540.

The previous prime is 856618537. The next prime is 856618571. The reversal of 856618541 is 145816658.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 431392900 + 425225641 = 20770^2 + 20621^2 .

It is a cyclic number.

It is not a de Polignac number, because 856618541 - 2² = 856618537 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 856618492 and 856618501.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (856618531) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 428309270 + 428309271.

It is an arithmetic number, because the mean of its divisors is an integer number (428309271).

Almost surely, 2^856618541 is an apocalyptic number.

It is an amenable number.

856618541 is a deficient number, since it is larger than the sum of its proper divisors (1).

856618541 is an equidigital number, since it uses as much as digits as its factorization.

856618541 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 230400, while the sum is 44.

The square root of 856618541 is about 29268.0464158440. The cubic root of 856618541 is about 949.7205238845.

The spelling of 856618541 in words is "eight hundred fifty-six million, six hundred eighteen thousand, five hundred forty-one".