21548243 has 2 divisors, whose sum is σ = 21548244. Its totient is φ = 21548242.

The previous prime is 21548237. The next prime is 21548251. The reversal of 21548243 is 34284512.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21548243 - 2⁴ = 21548227 is a prime.

It is not a weakly prime, because it can be changed into another prime (21548273) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10774121 + 10774122.

It is an arithmetic number, because the mean of its divisors is an integer number (10774122).

Almost surely, 2^21548243 is an apocalyptic number.

21548243 is a deficient number, since it is larger than the sum of its proper divisors (1).

21548243 is an equidigital number, since it uses as much as digits as its factorization.

21548243 is an evil number, because the sum of its binary digits is even.

The product of its digits is 7680, while the sum is 29.

The square root of 21548243 is about 4642.0085092554. The cubic root of 21548243 is about 278.2727125638.

The spelling of 21548243 in words is "twenty-one million, five hundred forty-eight thousand, two hundred forty-three".