21090063 has 8 divisors (see below), whose sum is σ = 28436400. Its totient is φ = 13901888.

The previous prime is 21090061. The next prime is 21090067. The reversal of 21090063 is 36009012.

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

It is a cyclic number.

It is not a de Polignac number, because 21090063 - 2¹ = 21090061 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21090061) 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 in 7 ways as a sum of consecutive naturals, for example, 39228 + ... + 39761.

It is an arithmetic number, because the mean of its divisors is an integer number (3554550).

Almost surely, 2^21090063 is an apocalyptic number.

21090063 is a deficient number, since it is larger than the sum of its proper divisors (7346337).

21090063 is an equidigital number, since it uses as much as digits as its factorization.

21090063 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 79081.

The product of its (nonzero) digits is 324, while the sum is 21.

The square root of 21090063 is about 4592.3918604579. The cubic root of 21090063 is about 276.2862630610.

Adding to 21090063 its reverse (36009012), we get a palindrome (57099075).

The spelling of 21090063 in words is "twenty-one million, ninety thousand, sixty-three".