2143121345 has 4 divisors (see below), whose sum is σ = 2571745620. Its totient is φ = 1714497072.

The previous prime is 2143121341. The next prime is 2143121413. The reversal of 2143121345 is 5431213412.

It is a happy number.

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

It can be written as a sum of positive squares in 2 ways, for example, as 401561521 + 1741559824 = 20039^2 + 41732^2 .

It is a cyclic number.

It is not a de Polignac number, because 2143121345 - 2² = 2143121341 is a prime.

It is not an unprimeable number, because it can be changed into a prime (2143121341) 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, 214312130 + ... + 214312139.

It is an arithmetic number, because the mean of its divisors is an integer number (642936405).

Almost surely, 2^2143121345 is an apocalyptic number.

It is an amenable number.

2143121345 is a deficient number, since it is larger than the sum of its proper divisors (428624275).

2143121345 is an equidigital number, since it uses as much as digits as its factorization.

2143121345 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 428624274.

The product of its digits is 2880, while the sum is 26.

The square root of 2143121345 is about 46293.8586099712. The cubic root of 2143121345 is about 1289.2849722114.

Adding to 2143121345 its reverse (5431213412), we get a palindrome (7574334757).

The spelling of 2143121345 in words is "two billion, one hundred forty-three million, one hundred twenty-one thousand, three hundred forty-five".