855263921 has 2 divisors, whose sum is σ = 855263922. Its totient is φ = 855263920.

The previous prime is 855263909. The next prime is 855263953. The reversal of 855263921 is 129362558.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 839550625 + 15713296 = 28975^2 + 3964^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-855263921 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (855263971) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 427631960 + 427631961.

It is an arithmetic number, because the mean of its divisors is an integer number (427631961).

Almost surely, 2^855263921 is an apocalyptic number.

It is an amenable number.

855263921 is a deficient number, since it is larger than the sum of its proper divisors (1).

855263921 is an equidigital number, since it uses as much as digits as its factorization.

855263921 is an evil number, because the sum of its binary digits is even.

The product of its digits is 129600, while the sum is 41.

The square root of 855263921 is about 29244.8956400942. The cubic root of 855263921 is about 949.2196439342.

The spelling of 855263921 in words is "eight hundred fifty-five million, two hundred sixty-three thousand, nine hundred twenty-one".