981540 has 144 divisors (see below), whose sum is σ = 3669120. Its totient is φ = 207360.

The previous prime is 981527. The next prime is 981569. The reversal of 981540 is 45189.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 23920 + ... + 23960.

It is an arithmetic number, because the mean of its divisors is an integer number (25480).

2⁹⁸¹⁵⁴⁰ is an apocalyptic number.

981540 is a gapful number since it is divisible by the number (90) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 981540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1834560).

981540 is an abundant number, since it is smaller than the sum of its proper divisors (2687580).

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

981540 is a wasteful number, since it uses less digits than its factorization.

981540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 82 (or 77 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 27.

The square root of 981540 is about 990.7270057892. The cubic root of 981540 is about 99.3808410000.

Subtracting from 981540 its product of nonzero digits (1440), we obtain a square (980100 = 990²).

It can be divided in two parts, 981 and 540, that added together give a square (1521 = 39²).

The spelling of 981540 in words is "nine hundred eighty-one thousand, five hundred forty".