21202123254 has 16 divisors (see below), whose sum is σ = 45666111792. Its totient is φ = 6523730208.

The previous prime is 21202123193. The next prime is 21202123277. The reversal of 21202123254 is 45232120212.

It is a super-3 number, since 3×21202123254³ (a number of 32 digits) contains 333 as substring.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 135910969 + ... + 135911124.

It is an arithmetic number, because the mean of its divisors is an integer number (2854131987).

Almost surely, 2^21202123254 is an apocalyptic number.

21202123254 is an abundant number, since it is smaller than the sum of its proper divisors (24463988538).

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

21202123254 is a wasteful number, since it uses less digits than its factorization.

21202123254 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 271822111.

The product of its (nonzero) digits is 1920, while the sum is 24.

Adding to 21202123254 its reverse (45232120212), we get a palindrome (66434243466).

The spelling of 21202123254 in words is "twenty-one billion, two hundred two million, one hundred twenty-three thousand, two hundred fifty-four".