21148573 has 2 divisors, whose sum is σ = 21148574. Its totient is φ = 21148572.

The previous prime is 21148559. The next prime is 21148597. The reversal of 21148573 is 37584112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17530969 + 3617604 = 4187^2 + 1902^2 .

It is a cyclic number.

It is not a de Polignac number, because 21148573 - 2¹⁷ = 21017501 is a prime.

It is equal to p_1338781 and since 21148573 and 1338781 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21148973) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10574286 + 10574287.

It is an arithmetic number, because the mean of its divisors is an integer number (10574287).

Almost surely, 2^21148573 is an apocalyptic number.

It is an amenable number.

21148573 is a deficient number, since it is larger than the sum of its proper divisors (1).

21148573 is an equidigital number, since it uses as much as digits as its factorization.

21148573 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6720, while the sum is 31.

The square root of 21148573 is about 4598.7577670497. The cubic root of 21148573 is about 276.5415267677.

It can be divided in two parts, 211 and 48573, that added together give a palindrome (48784).

The spelling of 21148573 in words is "twenty-one million, one hundred forty-eight thousand, five hundred seventy-three".