21121323 has 8 divisors (see below), whose sum is σ = 29070336. Its totient is φ = 13626600.

The previous prime is 21121319. The next prime is 21121333. The reversal of 21121323 is 32312112.

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

It is not a de Polignac number, because 21121323 - 2² = 21121319 is a prime.

It is a super-2 number, since 2×21121323² = 892220570540658, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21121333) 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, 113463 + ... + 113648.

It is an arithmetic number, because the mean of its divisors is an integer number (3633792).

Almost surely, 2^21121323 is an apocalyptic number.

21121323 is a deficient number, since it is larger than the sum of its proper divisors (7949013).

21121323 is a wasteful number, since it uses less digits than its factorization.

21121323 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 227145.

The product of its digits is 72, while the sum is 15.

The square root of 21121323 is about 4595.7940554381. The cubic root of 21121323 is about 276.4227008539.

Adding to 21121323 its reverse (32312112), we get a palindrome (53433435).

The spelling of 21121323 in words is "twenty-one million, one hundred twenty-one thousand, three hundred twenty-three".