21122123210 has 8 divisors (see below), whose sum is σ = 38019821796. Its totient is φ = 8448849280.

The previous prime is 21122123201. The next prime is 21122123213. The reversal of 21122123210 is 1232122112.

It can be written as a sum of positive squares in 2 ways, for example, as 20147247481 + 974875729 = 141941^2 + 31223^2 .

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

It is a super-2 number, since 2×21122123210² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21122123213) 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, 1056106151 + ... + 1056106170.

Almost surely, 2^21122123210 is an apocalyptic number.

21122123210 is a deficient number, since it is larger than the sum of its proper divisors (16897698586).

21122123210 is a wasteful number, since it uses less digits than its factorization.

21122123210 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2112212328.

The product of its (nonzero) digits is 96, while the sum is 17.

Adding to 21122123210 its reverse (1232122112), we get a palindrome (22354245322).

The spelling of 21122123210 in words is "twenty-one billion, one hundred twenty-two million, one hundred twenty-three thousand, two hundred ten".