856993013 has 2 divisors, whose sum is σ = 856993014. Its totient is φ = 856993012.

The previous prime is 856992977. The next prime is 856993037. The reversal of 856993013 is 310399658.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 853691524 + 3301489 = 29218^2 + 1817^2 .

It is a cyclic number.

It is not a de Polignac number, because 856993013 - 2¹² = 856988917 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (856993513) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 428496506 + 428496507.

It is an arithmetic number, because the mean of its divisors is an integer number (428496507).

Almost surely, 2^856993013 is an apocalyptic number.

It is an amenable number.

856993013 is a deficient number, since it is larger than the sum of its proper divisors (1).

856993013 is an equidigital number, since it uses as much as digits as its factorization.

856993013 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 174960, while the sum is 44.

The square root of 856993013 is about 29274.4430006789. The cubic root of 856993013 is about 949.8588942777.

The spelling of 856993013 in words is "eight hundred fifty-six million, nine hundred ninety-three thousand, thirteen".