851905989 has 24 divisors (see below), whose sum is σ = 1421364672. Its totient is φ = 485934720.

The previous prime is 851905979. The next prime is 851906051. The reversal of 851905989 is 989509158.

851905989 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 851905989 - 2⁹ = 851905477 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (851905909) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 251409 + ... + 254774.

It is an arithmetic number, because the mean of its divisors is an integer number (59223528).

Almost surely, 2^851905989 is an apocalyptic number.

It is an amenable number.

851905989 is a deficient number, since it is larger than the sum of its proper divisors (569458683).

851905989 is a wasteful number, since it uses less digits than its factorization.

851905989 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 506217 (or 506214 counting only the distinct ones).

The product of its (nonzero) digits is 1166400, while the sum is 54.

The square root of 851905989 is about 29187.4286123324. The cubic root of 851905989 is about 947.9757411140.

The spelling of 851905989 in words is "eight hundred fifty-one million, nine hundred five thousand, nine hundred eighty-nine".