990055778 has 8 divisors (see below), whose sum is σ = 1487800272. Its totient is φ = 494122356.

The previous prime is 990055777. The next prime is 990055783. The reversal of 990055778 is 877550099.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (990055771) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 451400 + ... + 453587.

It is an arithmetic number, because the mean of its divisors is an integer number (185975034).

Almost surely, 2^990055778 is an apocalyptic number.

990055778 is a deficient number, since it is larger than the sum of its proper divisors (497744494).

990055778 is a wasteful number, since it uses less digits than its factorization.

990055778 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 905536.

The product of its (nonzero) digits is 793800, while the sum is 50.

The square root of 990055778 is about 31465.1518032251. The cubic root of 990055778 is about 996.6742107211.

The spelling of 990055778 in words is "nine hundred ninety million, fifty-five thousand, seven hundred seventy-eight".