21123243042444 has 144 divisors (see below), whose sum is σ = 54476525376000. Its totient is φ = 6899245714560.

The previous prime is 21123243042383. The next prime is 21123243042469. The reversal of 21123243042444 is 44424034232112.

21123243042444 is a `hidden beast` number, since 2 + 1 + 1 + 2 + 324 + 304 + 24 + 4 + 4 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 21123243042399 and 21123243042408.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1337668189 + ... + 1337683979.

It is an arithmetic number, because the mean of its divisors is an integer number (378309204000).

Almost surely, 2^{21123243042444} 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 21123243042444, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27238262688000).

21123243042444 is an abundant number, since it is smaller than the sum of its proper divisors (33353282333556).

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

21123243042444 is a wasteful number, since it uses less digits than its factorization.

21123243042444 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17868 (or 17863 counting only the distinct ones).

The product of its (nonzero) digits is 147456, while the sum is 36.

Adding to 21123243042444 its reverse (44424034232112), we get a palindrome (65547277274556).

The spelling of 21123243042444 in words is "twenty-one trillion, one hundred twenty-three billion, two hundred forty-three million, forty-two thousand, four hundred forty-four".