2181520 has 80 divisors (see below), whose sum is σ = 5767488. Its totient is φ = 760320.

The previous prime is 2181503. The next prime is 2181539. The reversal of 2181520 is 251812.

It is a tau number, because it is divible by the number of its divisors (80).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 32527 + ... + 32593.

2^2181520 is an apocalyptic number.

2181520 is a gapful number since it is divisible by the number (20) 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 2181520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2883744).

2181520 is an abundant number, since it is smaller than the sum of its proper divisors (3585968).

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

2181520 is a wasteful number, since it uses less digits than its factorization.

2181520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 128 (or 122 counting only the distinct ones).

The product of its (nonzero) digits is 160, while the sum is 19.

The square root of 2181520 is about 1476.9969532805. The cubic root of 2181520 is about 129.6939546311.

It can be divided in two parts, 2181 and 520, that added together give a triangular number (2701 = T₇₃).

The spelling of 2181520 in words is "two million, one hundred eighty-one thousand, five hundred twenty".