21152643 has 8 divisors (see below), whose sum is σ = 29688000. Its totient is φ = 13359528.

The previous prime is 21152591. The next prime is 21152657. The reversal of 21152643 is 34625112.

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

It is not a de Polignac number, because 21152643 - 2¹⁰ = 21151619 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21152683) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 185493 + ... + 185606.

It is an arithmetic number, because the mean of its divisors is an integer number (3711000).

Almost surely, 2^21152643 is an apocalyptic number.

21152643 is a deficient number, since it is larger than the sum of its proper divisors (8535357).

21152643 is a wasteful number, since it uses less digits than its factorization.

21152643 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 371121.

The product of its digits is 1440, while the sum is 24.

The square root of 21152643 is about 4599.2002565664. The cubic root of 21152643 is about 276.5592655819.

Adding to 21152643 its reverse (34625112), we get a palindrome (55777755).

The spelling of 21152643 in words is "twenty-one million, one hundred fifty-two thousand, six hundred forty-three".