21123253122 has 16 divisors (see below), whose sum is σ = 43609297152. Its totient is φ = 6813952560.

The previous prime is 21123253111. The next prime is 21123253127. The reversal of 21123253122 is 22135232112.

It is a junction number, because it is equal to n+sod(n) for n = 21123253092 and 21123253101.

It is not an unprimeable number, because it can be changed into a prime (21123253127) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 56782753 + ... + 56783124.

It is an arithmetic number, because the mean of its divisors is an integer number (2725581072).

Almost surely, 2^21123253122 is an apocalyptic number.

21123253122 is an abundant number, since it is smaller than the sum of its proper divisors (22486044030).

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

21123253122 is a wasteful number, since it uses less digits than its factorization.

21123253122 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 113565913.

The product of its digits is 1440, while the sum is 24.

Adding to 21123253122 its reverse (22135232112), we get a palindrome (43258485234).

The spelling of 21123253122 in words is "twenty-one billion, one hundred twenty-three million, two hundred fifty-three thousand, one hundred twenty-two".