21106573 has 2 divisors, whose sum is σ = 21106574. Its totient is φ = 21106572.

The previous prime is 21106543. The next prime is 21106583. The reversal of 21106573 is 37560112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12938409 + 8168164 = 3597^2 + 2858^2 .

It is a cyclic number.

It is not a de Polignac number, because 21106573 - 2¹³ = 21098381 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21106523) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10553286 + 10553287.

It is an arithmetic number, because the mean of its divisors is an integer number (10553287).

Almost surely, 2^21106573 is an apocalyptic number.

It is an amenable number.

21106573 is a deficient number, since it is larger than the sum of its proper divisors (1).

21106573 is an equidigital number, since it uses as much as digits as its factorization.

21106573 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1260, while the sum is 25.

The square root of 21106573 is about 4594.1890470463. The cubic root of 21106573 is about 276.3583396029.

Adding to 21106573 its reverse (37560112), we get a palindrome (58666685).

The spelling of 21106573 in words is "twenty-one million, one hundred six thousand, five hundred seventy-three".