21144154424 has 8 divisors (see below), whose sum is σ = 39645289560. Its totient is φ = 10572077208.

The previous prime is 21144154309. The next prime is 21144154433. The reversal of 21144154424 is 42445144112.

It is a tau number, because it is divible by the number of its divisors (8).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1321509644 + ... + 1321509659.

It is an arithmetic number, because the mean of its divisors is an integer number (4955661195).

Almost surely, 2^21144154424 is an apocalyptic number.

It is an amenable number.

21144154424 is a deficient number, since it is larger than the sum of its proper divisors (18501135136).

21144154424 is a wasteful number, since it uses less digits than its factorization.

21144154424 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2643019309 (or 2643019305 counting only the distinct ones).

The product of its digits is 20480, while the sum is 32.

Adding to 21144154424 its reverse (42445144112), we get a palindrome (63589298536).

The spelling of 21144154424 in words is "twenty-one billion, one hundred forty-four million, one hundred fifty-four thousand, four hundred twenty-four".