990891006 has 128 divisors (see below), whose sum is σ = 2444918784. Its totient is φ = 261740160.

The previous prime is 990890903. The next prime is 990891029. The reversal of 990891006 is 600198099.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 3227505 + ... + 3227811.

It is an arithmetic number, because the mean of its divisors is an integer number (19100928).

Almost surely, 2^990891006 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 990891006, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1222459392).

990891006 is an abundant number, since it is smaller than the sum of its proper divisors (1454027778).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

990891006 is a wasteful number, since it uses less digits than its factorization.

990891006 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 454.

The product of its (nonzero) digits is 34992, while the sum is 42.

The square root of 990891006 is about 31478.4212755341. The cubic root of 990891006 is about 996.9544024187.

The spelling of 990891006 in words is "nine hundred ninety million, eight hundred ninety-one thousand, six".