21123132123 has 8 divisors (see below), whose sum is σ = 28237713408. Its totient is φ = 14045319464.

The previous prime is 21123132109. The next prime is 21123132157. The reversal of 21123132123 is 32123132112.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21123132123 - 2⁸ = 21123131867 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21123132123.

It is not an unprimeable number, because it can be changed into a prime (21123132103) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9190815 + ... + 9193112.

It is an arithmetic number, because the mean of its divisors is an integer number (3529714176).

Almost surely, 2^21123132123 is an apocalyptic number.

21123132123 is a deficient number, since it is larger than the sum of its proper divisors (7114581285).

21123132123 is a wasteful number, since it uses less digits than its factorization.

21123132123 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18384313.

The product of its digits is 432, while the sum is 21.

Adding to 21123132123 its reverse (32123132112), we get a palindrome (53246264235).

The spelling of 21123132123 in words is "twenty-one billion, one hundred twenty-three million, one hundred thirty-two thousand, one hundred twenty-three".