856641479 has 2 divisors, whose sum is σ = 856641480. Its totient is φ = 856641478.

The previous prime is 856641403. The next prime is 856641493. The reversal of 856641479 is 974146658.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-856641479 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (856611479) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 428320739 + 428320740.

It is an arithmetic number, because the mean of its divisors is an integer number (428320740).

Almost surely, 2^856641479 is an apocalyptic number.

856641479 is a deficient number, since it is larger than the sum of its proper divisors (1).

856641479 is an equidigital number, since it uses as much as digits as its factorization.

856641479 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1451520, while the sum is 50.

The square root of 856641479 is about 29268.4382740180. The cubic root of 856641479 is about 949.7290008178.

The spelling of 856641479 in words is "eight hundred fifty-six million, six hundred forty-one thousand, four hundred seventy-nine".