21202123210 has 8 divisors (see below), whose sum is σ = 38163821796. Its totient is φ = 8480849280.

The previous prime is 21202123193. The next prime is 21202123277. The reversal of 21202123210 is 1232120212.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 21167631081 + 34492129 = 145491^2 + 5873^2 .

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

It is a super-2 number, since 2×21202123210² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1060106151 + ... + 1060106170.

Almost surely, 2^21202123210 is an apocalyptic number.

21202123210 is a deficient number, since it is larger than the sum of its proper divisors (16961698586).

21202123210 is a wasteful number, since it uses less digits than its factorization.

21202123210 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2120212328.

The product of its (nonzero) digits is 96, while the sum is 16.

Adding to 21202123210 its reverse (1232120212), we get a palindrome (22434243422).

The spelling of 21202123210 in words is "twenty-one billion, two hundred two million, one hundred twenty-three thousand, two hundred ten".