21152842 has 8 divisors (see below), whose sum is σ = 31838436. Its totient is φ = 10540032.

The previous prime is 21152797. The next prime is 21152849. The reversal of 21152842 is 24825112.

It can be written as a sum of positive squares in 2 ways, for example, as 20985561 + 167281 = 4581^2 + 409^2 .

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

It is not an unprimeable number, because it can be changed into a prime (21152849) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 17463 + ... + 18634.

Almost surely, 2^21152842 is an apocalyptic number.

21152842 is a deficient number, since it is larger than the sum of its proper divisors (10685594).

21152842 is a wasteful number, since it uses less digits than its factorization.

21152842 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36392.

The product of its digits is 1280, while the sum is 25.

The square root of 21152842 is about 4599.2218907115. The cubic root of 21152842 is about 276.5601328513.

Adding to 21152842 its reverse (24825112), we get a palindrome (45977954).

The spelling of 21152842 in words is "twenty-one million, one hundred fifty-two thousand, eight hundred forty-two".