851905990 has 16 divisors (see below), whose sum is σ = 1651387248. Its totient is φ = 314549856.

The previous prime is 851905979. The next prime is 851906051. The reversal of 851905990 is 99509158.

851905990 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a self number, because there is not a number n which added to its sum of digits gives 851905990.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3276432 + ... + 3276691.

It is an arithmetic number, because the mean of its divisors is an integer number (103211703).

Almost surely, 2^851905990 is an apocalyptic number.

851905990 is a deficient number, since it is larger than the sum of its proper divisors (799481258).

851905990 is a wasteful number, since it uses less digits than its factorization.

851905990 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6553143.

The product of its (nonzero) digits is 145800, while the sum is 46.

The square root of 851905990 is about 29187.4286294631. The cubic root of 851905990 is about 947.9757414849.

The spelling of 851905990 in words is "eight hundred fifty-one million, nine hundred five thousand, nine hundred ninety".