2121530240 has 128 divisors (see below), whose sum is σ = 5232820320. Its totient is φ = 821985280.

The previous prime is 2121530239. The next prime is 2121530261. The reversal of 2121530240 is 420351212.

It is a tau number, because it is divible by the number of its divisors (128).

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a congruent number.

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 15 ways as a sum of consecutive naturals, for example, 6113747 + ... + 6114093.

Almost surely, 2^2121530240 is an apocalyptic number.

2121530240 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 2121530240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2616410160).

2121530240 is an abundant number, since it is smaller than the sum of its proper divisors (3111290080).

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

2121530240 is a wasteful number, since it uses less digits than its factorization.

2121530240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 640 (or 628 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 20.

The square root of 2121530240 is about 46060.0720798394. The cubic root of 2121530240 is about 1284.9406705992.

Adding to 2121530240 its reverse (420351212), we get a palindrome (2541881452).

The spelling of 2121530240 in words is "two billion, one hundred twenty-one million, five hundred thirty thousand, two hundred forty".