21210340044 has 24 divisors (see below), whose sum is σ = 51197373360. Its totient is φ = 6826316224.

The previous prime is 21210339991. The next prime is 21210340049. The reversal of 21210340044 is 44004301212.

It is a self number, because there is not a number n which added to its sum of digits gives 21210340044.

It is not an unprimeable number, because it can be changed into a prime (21210340049) 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, 30474279 + ... + 30474974.

It is an arithmetic number, because the mean of its divisors is an integer number (2133223890).

Almost surely, 2^21210340044 is an apocalyptic number.

It is an amenable number.

21210340044 is an abundant number, since it is smaller than the sum of its proper divisors (29987033316).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21210340044 is a wasteful number, since it uses less digits than its factorization.

21210340044 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 60949289 (or 60949287 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 21.

Adding to 21210340044 its reverse (44004301212), we get a palindrome (65214641256).

The spelling of 21210340044 in words is "twenty-one billion, two hundred ten million, three hundred forty thousand, forty-four".