21144111012 has 72 divisors (see below), whose sum is σ = 59570128800. Its totient is φ = 6284314368.

The previous prime is 21144111011. The next prime is 21144111077. The reversal of 21144111012 is 21011144112.

21144111012 is a `hidden beast` number, since 211 + 441 + 1 + 1 + 0 + 12 = 666.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is not an unprimeable number, because it can be changed into a prime (21144111011) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 897562 + ... + 920817.

It is an arithmetic number, because the mean of its divisors is an integer number (827362900).

Almost surely, 2^21144111012 is an apocalyptic number.

It is an amenable number.

21144111012 is an abundant number, since it is smaller than the sum of its proper divisors (38426017788).

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

21144111012 is a wasteful number, since it uses less digits than its factorization.

21144111012 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1818425 (or 1818420 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 18.

Adding to 21144111012 its reverse (21011144112), we get a palindrome (42155255124).

The spelling of 21144111012 in words is "twenty-one billion, one hundred forty-four million, one hundred eleven thousand, twelve".