21012303 has 8 divisors (see below), whose sum is σ = 30171568. Its totient is φ = 12930624.

The previous prime is 21012301. The next prime is 21012307. The reversal of 21012303 is 30321012.

It is a happy number.

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

It is not a de Polignac number, because 21012303 - 2¹ = 21012301 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21012301) 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, 269350 + ... + 269427.

It is an arithmetic number, because the mean of its divisors is an integer number (3771446).

Almost surely, 2^21012303 is an apocalyptic number.

21012303 is a deficient number, since it is larger than the sum of its proper divisors (9159265).

21012303 is a wasteful number, since it uses less digits than its factorization.

21012303 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 538793.

The product of its (nonzero) digits is 36, while the sum is 12.

The square root of 21012303 is about 4583.9178657563. The cubic root of 21012303 is about 275.9462849678.

Adding to 21012303 its reverse (30321012), we get a palindrome (51333315).

It can be divided in two parts, 21012 and 303, that multiplied together give a palindrome (6366636).

The spelling of 21012303 in words is "twenty-one million, twelve thousand, three hundred three".