21121210223 has 4 divisors (see below), whose sum is σ = 21181729800. Its totient is φ = 21060690648.

The previous prime is 21121210171. The next prime is 21121210237. The reversal of 21121210223 is 32201212112.

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 21121210223 - 2²⁶ = 21054101359 is a prime.

It is a super-2 number, since 2×21121210223² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21121210723) 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, 30259265 + ... + 30259962.

It is an arithmetic number, because the mean of its divisors is an integer number (5295432450).

Almost surely, 2^21121210223 is an apocalyptic number.

21121210223 is a deficient number, since it is larger than the sum of its proper divisors (60519577).

21121210223 is an equidigital number, since it uses as much as digits as its factorization.

21121210223 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 60519576.

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

Adding to 21121210223 its reverse (32201212112), we get a palindrome (53322422335).

The spelling of 21121210223 in words is "twenty-one billion, one hundred twenty-one million, two hundred ten thousand, two hundred twenty-three".