2123432345 has 16 divisors (see below), whose sum is σ = 2791046160. Its totient is φ = 1543686144.

The previous prime is 2123432341. The next prime is 2123432347. The reversal of 2123432345 is 5432343212.

It is a happy number.

2123432345 is an esthetic number in base 10, because in such base its adjacent digits differ by 1.

It can be written as a sum of positive squares in 8 ways, for example, as 12581209 + 2110851136 = 3547^2 + 45944^2 .

It is a cyclic number.

It is not a de Polignac number, because 2123432345 - 2² = 2123432341 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (29).

It is an alternating number because its digits alternate between even and odd.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (2123432341) 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, 428252 + ... + 433181.

It is an arithmetic number, because the mean of its divisors is an integer number (174440385).

Almost surely, 2^2123432345 is an apocalyptic number.

It is an amenable number.

2123432345 is a deficient number, since it is larger than the sum of its proper divisors (667613815).

2123432345 is a wasteful number, since it uses less digits than its factorization.

2123432345 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 861484.

The product of its digits is 17280, while the sum is 29.

The square root of 2123432345 is about 46080.7155434896. The cubic root of 2123432345 is about 1285.3245699119.

Adding to 2123432345 its reverse (5432343212), we get a palindrome (7555775557).

It can be divided in two parts, 2123 and 432345, that multiplied together give a triangular number (917868435 = T₄₂₈₄₅).

The spelling of 2123432345 in words is "two billion, one hundred twenty-three million, four hundred thirty-two thousand, three hundred forty-five".