21213301 has 4 divisors (see below), whose sum is σ = 21266604. Its totient is φ = 21160000.

The previous prime is 21213293. The next prime is 21213341. The reversal of 21213301 is 10331212.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 21150801 + 62500 = 4599^2 + 250^2 .

It is a cyclic number.

It is not a de Polignac number, because 21213301 - 2³ = 21213293 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21213341) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 26050 + ... + 26851.

It is an arithmetic number, because the mean of its divisors is an integer number (5316651).

Almost surely, 2^21213301 is an apocalyptic number.

It is an amenable number.

21213301 is a deficient number, since it is larger than the sum of its proper divisors (53303).

21213301 is an equidigital number, since it uses as much as digits as its factorization.

21213301 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53302.

The product of its (nonzero) digits is 36, while the sum is 13.

The square root of 21213301 is about 4605.7899431042. The cubic root of 21213301 is about 276.8233700420.

Adding to 21213301 its reverse (10331212), we get a palindrome (31544513).

The spelling of 21213301 in words is "twenty-one million, two hundred thirteen thousand, three hundred one".