2121543240 has 64 divisors (see below), whose sum is σ = 6472526400. Its totient is φ = 556154112.

The previous prime is 2121543233. The next prime is 2121543241. The reversal of 2121543240 is 423451212.

2121543240 is digitally balanced in base 4, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a self number, because there is not a number n which added to its sum of digits gives 2121543240.

It is not an unprimeable number, because it can be changed into a prime (2121543241) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 142747 + ... + 156906.

It is an arithmetic number, because the mean of its divisors is an integer number (101133225).

Almost surely, 2^2121543240 is an apocalyptic number.

2121543240 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

2121543240 is an abundant number, since it is smaller than the sum of its proper divisors (4350983160).

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

2121543240 is a wasteful number, since it uses less digits than its factorization.

2121543240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 299726 (or 299722 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 24.

The square root of 2121543240 is about 46060.2131996803. The cubic root of 2121543240 is about 1284.9432951505.

Adding to 2121543240 its reverse (423451212), we get a palindrome (2544994452).

The spelling of 2121543240 in words is "two billion, one hundred twenty-one million, five hundred forty-three thousand, two hundred forty".