21121123343 has 4 divisors (see below), whose sum is σ = 21121692240. Its totient is φ = 21120554448.

The previous prime is 21121123337. The next prime is 21121123363. The reversal of 21121123343 is 34332112112.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21121123343 is a prime.

It is a super-2 number, since 2×21121123343² (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 (21121123363) 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, 224555 + ... + 304412.

It is an arithmetic number, because the mean of its divisors is an integer number (5280423060).

Almost surely, 2^21121123343 is an apocalyptic number.

21121123343 is a deficient number, since it is larger than the sum of its proper divisors (568897).

21121123343 is an equidigital number, since it uses as much as digits as its factorization.

21121123343 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 568896.

The product of its digits is 864, while the sum is 23.

Adding to 21121123343 its reverse (34332112112), we get a palindrome (55453235455).

The spelling of 21121123343 in words is "twenty-one billion, one hundred twenty-one million, one hundred twenty-three thousand, three hundred forty-three".