858455921 has 2 divisors, whose sum is σ = 858455922. Its totient is φ = 858455920.

The previous prime is 858455911. The next prime is 858455947. The reversal of 858455921 is 129554858.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 790228321 + 68227600 = 28111^2 + 8260^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-858455921 is a prime.

It is not a weakly prime, because it can be changed into another prime (858455911) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 429227960 + 429227961.

It is an arithmetic number, because the mean of its divisors is an integer number (429227961).

Almost surely, 2^858455921 is an apocalyptic number.

It is an amenable number.

858455921 is a deficient number, since it is larger than the sum of its proper divisors (1).

858455921 is an equidigital number, since it uses as much as digits as its factorization.

858455921 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 576000, while the sum is 47.

The square root of 858455921 is about 29299.4184413275. The cubic root of 858455921 is about 950.3990644753.

The spelling of 858455921 in words is "eight hundred fifty-eight million, four hundred fifty-five thousand, nine hundred twenty-one".