990478887 has 4 divisors (see below), whose sum is σ = 1320638520. Its totient is φ = 660319256.

The previous prime is 990478849. The next prime is 990478903. The reversal of 990478887 is 788874099.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 990478887 - 2²² = 986284583 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 990478887.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (990478387) 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, 165079812 + ... + 165079817.

It is an arithmetic number, because the mean of its divisors is an integer number (330159630).

Almost surely, 2^990478887 is an apocalyptic number.

990478887 is a deficient number, since it is larger than the sum of its proper divisors (330159633).

990478887 is a wasteful number, since it uses less digits than its factorization.

990478887 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 330159632.

The product of its (nonzero) digits is 8128512, while the sum is 60.

The square root of 990478887 is about 31471.8745390229. The cubic root of 990478887 is about 996.8161696489.

The spelling of 990478887 in words is "nine hundred ninety million, four hundred seventy-eight thousand, eight hundred eighty-seven".