21043552123 has 4 divisors (see below), whose sum is σ = 22956602328. Its totient is φ = 19130501920.

The previous prime is 21043552111. The next prime is 21043552133. The reversal of 21043552123 is 32125534012.

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 21043552123 - 2⁹ = 21043551611 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21043552091 and 21043552100.

It is not an unprimeable number, because it can be changed into a prime (21043552133) 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, 956525086 + ... + 956525107.

It is an arithmetic number, because the mean of its divisors is an integer number (5739150582).

Almost surely, 2^21043552123 is an apocalyptic number.

21043552123 is a deficient number, since it is larger than the sum of its proper divisors (1913050205).

21043552123 is a wasteful number, since it uses less digits than its factorization.

21043552123 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1913050204.

The product of its (nonzero) digits is 7200, while the sum is 28.

The spelling of 21043552123 in words is "twenty-one billion, forty-three million, five hundred fifty-two thousand, one hundred twenty-three".