2121005243 has 4 divisors (see below), whose sum is σ = 2424006000. Its totient is φ = 1818004488.

The previous prime is 2121005239. The next prime is 2121005269. The reversal of 2121005243 is 3425001212.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 2121005243 - 2² = 2121005239 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2121005203) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 151500368 + ... + 151500381.

It is an arithmetic number, because the mean of its divisors is an integer number (606001500).

Almost surely, 2^2121005243 is an apocalyptic number.

2121005243 is a deficient number, since it is larger than the sum of its proper divisors (303000757).

2121005243 is an equidigital number, since it uses as much as digits as its factorization.

2121005243 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 303000756.

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

The square root of 2121005243 is about 46054.3726805610. The cubic root of 2121005243 is about 1284.8346707511.

Adding to 2121005243 its reverse (3425001212), we get a palindrome (5546006455).

The spelling of 2121005243 in words is "two billion, one hundred twenty-one million, five thousand, two hundred forty-three".