21120034144 has 96 divisors (see below), whose sum is σ = 47966349312. Its totient is φ = 9063552000.

The previous prime is 21120034127. The next prime is 21120034147. The reversal of 21120034144 is 44143002112.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (22).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21120034147) 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, 423789 + ... + 470995.

It is an arithmetic number, because the mean of its divisors is an integer number (499649472).

Almost surely, 2^21120034144 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21120034144, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23983174656).

21120034144 is an abundant number, since it is smaller than the sum of its proper divisors (26846315168).

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

21120034144 is a wasteful number, since it uses less digits than its factorization.

21120034144 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47300 (or 47292 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 22.

Adding to 21120034144 its reverse (44143002112), we get a palindrome (65263036256).

The spelling of 21120034144 in words is "twenty-one billion, one hundred twenty million, thirty-four thousand, one hundred forty-four".