21324361 has 2 divisors, whose sum is σ = 21324362. Its totient is φ = 21324360.

The previous prime is 21324313. The next prime is 21324389. The reversal of 21324361 is 16342312.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21206025 + 118336 = 4605^2 + 344^2 .

It is a cyclic number.

It is not a de Polignac number, because 21324361 - 2¹⁵ = 21291593 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21324301) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10662180 + 10662181.

It is an arithmetic number, because the mean of its divisors is an integer number (10662181).

Almost surely, 2^21324361 is an apocalyptic number.

It is an amenable number.

21324361 is a deficient number, since it is larger than the sum of its proper divisors (1).

21324361 is an equidigital number, since it uses as much as digits as its factorization.

21324361 is an evil number, because the sum of its binary digits is even.

The product of its digits is 864, while the sum is 22.

The square root of 21324361 is about 4617.8307677956. The cubic root of 21324361 is about 277.3056226101.

Adding to 21324361 its reverse (16342312), we get a palindrome (37666673).

The spelling of 21324361 in words is "twenty-one million, three hundred twenty-four thousand, three hundred sixty-one".