21233402123 has 4 divisors (see below), whose sum is σ = 21321507768. Its totient is φ = 21145296480.

The previous prime is 21233402119. The next prime is 21233402159. The reversal of 21233402123 is 32120433212.

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 21233402123 - 2² = 21233402119 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21233402023) 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, 44052461 + ... + 44052942.

It is an arithmetic number, because the mean of its divisors is an integer number (5330376942).

Almost surely, 2^21233402123 is an apocalyptic number.

21233402123 is a deficient number, since it is larger than the sum of its proper divisors (88105645).

21233402123 is an equidigital number, since it uses as much as digits as its factorization.

21233402123 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 88105644.

The product of its (nonzero) digits is 1728, while the sum is 23.

Adding to 21233402123 its reverse (32120433212), we get a palindrome (53353835335).

The spelling of 21233402123 in words is "twenty-one billion, two hundred thirty-three million, four hundred two thousand, one hundred twenty-three".