21312301 has 4 divisors (see below), whose sum is σ = 21324412. Its totient is φ = 21300192.

The previous prime is 21312299. The next prime is 21312323. The reversal of 21312301 is 10321312.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 1687401 + 19624900 = 1299^2 + 4430^2 .

It is a cyclic number.

It is not a de Polignac number, because 21312301 - 2¹ = 21312299 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 (21312341) 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, 2850 + ... + 7123.

It is an arithmetic number, because the mean of its divisors is an integer number (5331103).

Almost surely, 2^21312301 is an apocalyptic number.

It is an amenable number.

21312301 is a deficient number, since it is larger than the sum of its proper divisors (12111).

21312301 is an equidigital number, since it uses as much as digits as its factorization.

21312301 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12110.

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

The square root of 21312301 is about 4616.5247751962. The cubic root of 21312301 is about 277.2533359872.

Adding to 21312301 its reverse (10321312), we get a palindrome (31633613).

The spelling of 21312301 in words is "twenty-one million, three hundred twelve thousand, three hundred one".