2123543656 has 16 divisors (see below), whose sum is σ = 4287924900. Its totient is φ = 980097024.

The previous prime is 2123543641. The next prime is 2123543677. The reversal of 2123543656 is 6563453212.

It can be written as a sum of positive squares in 2 ways, for example, as 1694639556 + 428904100 = 41166^2 + 20710^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10209241 + ... + 10209448.

Almost surely, 2^2123543656 is an apocalyptic number.

2123543656 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is an amenable number.

2123543656 is an abundant number, since it is smaller than the sum of its proper divisors (2164381244).

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

2123543656 is a wasteful number, since it uses less digits than its factorization.

2123543656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20418708 (or 20418704 counting only the distinct ones).

The product of its digits is 129600, while the sum is 37.

The square root of 2123543656 is about 46081.9233105564. The cubic root of 2123543656 is about 1285.3470285606.

Adding to 2123543656 its reverse (6563453212), we get a palindrome (8686996868).

The spelling of 2123543656 in words is "two billion, one hundred twenty-three million, five hundred forty-three thousand, six hundred fifty-six".