21121213403444 has 24 divisors (see below), whose sum is σ = 46082647426368. Its totient is φ = 8229044183040.

The previous prime is 21121213403417. The next prime is 21121213403447. The reversal of 21121213403444 is 44430431212112.

It is a super-2 number, since 2×21121213403444² (a number of 27 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21121213403444.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21121213403447) 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, 34287683789 + ... + 34287684404.

It is an arithmetic number, because the mean of its divisors is an integer number (1920110309432).

Almost surely, 2^{21121213403444} is an apocalyptic number.

It is an amenable number.

21121213403444 is an abundant number, since it is smaller than the sum of its proper divisors (24961434022924).

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

21121213403444 is a wasteful number, since it uses less digits than its factorization.

21121213403444 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 68575368215 (or 68575368213 counting only the distinct ones).

The product of its (nonzero) digits is 18432, while the sum is 32.

Adding to 21121213403444 its reverse (44430431212112), we get a palindrome (65551644615556).

The spelling of 21121213403444 in words is "twenty-one trillion, one hundred twenty-one billion, two hundred thirteen million, four hundred three thousand, four hundred forty-four".