21148823 has 2 divisors, whose sum is σ = 21148824. Its totient is φ = 21148822.

The previous prime is 21148811. The next prime is 21148847. The reversal of 21148823 is 32884112.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21148823 - 2⁴ = 21148807 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21148123) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10574411 + 10574412.

It is an arithmetic number, because the mean of its divisors is an integer number (10574412).

Almost surely, 2^21148823 is an apocalyptic number.

21148823 is a deficient number, since it is larger than the sum of its proper divisors (1).

21148823 is an equidigital number, since it uses as much as digits as its factorization.

21148823 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3072, while the sum is 29.

The square root of 21148823 is about 4598.7849482227. The cubic root of 21148823 is about 276.5426164411.

The spelling of 21148823 in words is "twenty-one million, one hundred forty-eight thousand, eight hundred twenty-three".