981000090 has 144 divisors (see below), whose sum is σ = 2985844680. Its totient is φ = 222808320.

The previous prime is 981000089. The next prime is 981000103. The reversal of 981000090 is 90000189.

It can be written as a sum of positive squares in 4 ways, for example, as 781258401 + 199741689 = 27951^2 + 14133^2 .

It is a super-2 number, since 2×981000090² = 1924722353160016200, which contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 797596 + ... + 798824.

Almost surely, 2^981000090 is an apocalyptic number.

981000090 is a gapful number since it is divisible by the number (90) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 981000090, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1492922340).

981000090 is an abundant number, since it is smaller than the sum of its proper divisors (2004844590).

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

981000090 is a wasteful number, since it uses less digits than its factorization.

981000090 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1437 (or 1427 counting only the distinct ones).

The product of its (nonzero) digits is 648, while the sum is 27.

The square root of 981000090 is about 31320.9209634710. The cubic root of 981000090 is about 993.6261571078.

The spelling of 981000090 in words is "nine hundred eighty-one million, ninety", and thus it is an aban number.