21210440343 has 16 divisors (see below), whose sum is σ = 29230924800. Its totient is φ = 13666314240.

The previous prime is 21210440309. The next prime is 21210440347. The reversal of 21210440343 is 34304401212.

It is not a de Polignac number, because 21210440343 - 2¹⁷ = 21210309271 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21210440347) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 76773 + ... + 219806.

It is an arithmetic number, because the mean of its divisors is an integer number (1826932800).

Almost surely, 2^21210440343 is an apocalyptic number.

21210440343 is a deficient number, since it is larger than the sum of its proper divisors (8020484457).

21210440343 is a wasteful number, since it uses less digits than its factorization.

21210440343 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 297382.

The product of its (nonzero) digits is 2304, while the sum is 24.

Adding to 21210440343 its reverse (34304401212), we get a palindrome (55514841555).

The spelling of 21210440343 in words is "twenty-one billion, two hundred ten million, four hundred forty thousand, three hundred forty-three".