21154443242 has 8 divisors (see below), whose sum is σ = 31734501732. Its totient is φ = 10576276000.

The previous prime is 21154443227. The next prime is 21154443259. The reversal of 21154443242 is 24234445112.

It can be written as a sum of positive squares in 2 ways, for example, as 20050276801 + 1104166441 = 141599^2 + 33229^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a junction number, because it is equal to n+sod(n) for n = 21154443199 and 21154443208.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 444509 + ... + 489792.

Almost surely, 2^21154443242 is an apocalyptic number.

21154443242 is a deficient number, since it is larger than the sum of its proper divisors (10580058490).

21154443242 is a wasteful number, since it uses less digits than its factorization.

21154443242 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 945624.

The product of its digits is 30720, while the sum is 32.

Adding to 21154443242 its reverse (24234445112), we get a palindrome (45388888354).

The spelling of 21154443242 in words is "twenty-one billion, one hundred fifty-four million, four hundred forty-three thousand, two hundred forty-two".