2129540 has 72 divisors (see below), whose sum is σ = 5429592. Its totient is φ = 698880.

The previous prime is 2129537. The next prime is 2129549. The reversal of 2129540 is 459212.

It can be written as a sum of positive squares in 4 ways, for example, as 50176 + 2079364 = 224^2 + 1442^2 .

It is a super-2 number, since 2×2129540² = 9069881223200, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (2129549) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 40154 + ... + 40206.

It is an arithmetic number, because the mean of its divisors is an integer number (75411).

2^2129540 is an apocalyptic number.

2129540 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 2129540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2714796).

2129540 is an abundant number, since it is smaller than the sum of its proper divisors (3300052).

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

2129540 is a wasteful number, since it uses less digits than its factorization.

2129540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 117 (or 108 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 23.

The square root of 2129540 is about 1459.2943500199. The cubic root of 2129540 is about 128.6555721982.

The spelling of 2129540 in words is "two million, one hundred twenty-nine thousand, five hundred forty".