21152243 has 8 divisors (see below), whose sum is σ = 24220512. Its totient is φ = 18095616.

The previous prime is 21152239. The next prime is 21152291. The reversal of 21152243 is 34225112.

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

It is not a de Polignac number, because 21152243 - 2² = 21152239 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21152143) 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, 1421 + ... + 6657.

It is an arithmetic number, because the mean of its divisors is an integer number (3027564).

Almost surely, 2^21152243 is an apocalyptic number.

21152243 is a deficient number, since it is larger than the sum of its proper divisors (3068269).

21152243 is an equidigital number, since it uses as much as digits as its factorization.

21152243 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5821.

The product of its digits is 480, while the sum is 20.

The square root of 21152243 is about 4599.1567705396. The cubic root of 21152243 is about 276.5575223103.

Adding to 21152243 its reverse (34225112), we get a palindrome (55377355).

The spelling of 21152243 in words is "twenty-one million, one hundred fifty-two thousand, two hundred forty-three".