21210301243 has 8 divisors (see below), whose sum is σ = 22509131040. Its totient is φ = 19917156480.

The previous prime is 21210301169. The next prime is 21210301279. The reversal of 21210301243 is 34210301212.

It is a happy number.

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

It is not a de Polignac number, because 21210301243 - 2¹³ = 21210293051 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21210301243.

It is not an unprimeable number, because it can be changed into a prime (21210301043) 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, 1413568 + ... + 1428493.

It is an arithmetic number, because the mean of its divisors is an integer number (2813641380).

Almost surely, 2^21210301243 is an apocalyptic number.

21210301243 is a deficient number, since it is larger than the sum of its proper divisors (1298829797).

21210301243 is a wasteful number, since it uses less digits than its factorization.

21210301243 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2842517.

The product of its (nonzero) digits is 288, while the sum is 19.

Adding to 21210301243 its reverse (34210301212), we get a palindrome (55420602455).

The spelling of 21210301243 in words is "twenty-one billion, two hundred ten million, three hundred one thousand, two hundred forty-three".