21121202343 has 4 divisors (see below), whose sum is σ = 28161603128. Its totient is φ = 14080801560.

The previous prime is 21121202327. The next prime is 21121202353. The reversal of 21121202343 is 34320212112.

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

It is not a de Polignac number, because 21121202343 - 2⁴ = 21121202327 is a prime.

It is a super-2 number, since 2×21121202343² (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 (21121202353) 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, 3520200388 + ... + 3520200393.

It is an arithmetic number, because the mean of its divisors is an integer number (7040400782).

Almost surely, 2^21121202343 is an apocalyptic number.

21121202343 is a deficient number, since it is larger than the sum of its proper divisors (7040400785).

21121202343 is an equidigital number, since it uses as much as digits as its factorization.

21121202343 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7040400784.

The product of its (nonzero) digits is 576, while the sum is 21.

Adding to 21121202343 its reverse (34320212112), we get a palindrome (55441414455).

The spelling of 21121202343 in words is "twenty-one billion, one hundred twenty-one million, two hundred two thousand, three hundred forty-three".