21361433 has 4 divisors (see below), whose sum is σ = 21472308. Its totient is φ = 21250560.

The previous prime is 21361427. The next prime is 21361447. The reversal of 21361433 is 33416312.

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 10259209 + 11102224 = 3203^2 + 3332^2 .

It is a cyclic number.

It is not a de Polignac number, because 21361433 - 2¹⁸ = 21099289 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21361399 and 21361408.

It is not an unprimeable number, because it can be changed into a prime (21361423) 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 3 ways as a sum of consecutive naturals, for example, 55148 + ... + 55533.

It is an arithmetic number, because the mean of its divisors is an integer number (5368077).

Almost surely, 2^21361433 is an apocalyptic number.

It is an amenable number.

21361433 is a deficient number, since it is larger than the sum of its proper divisors (110875).

21361433 is a wasteful number, since it uses less digits than its factorization.

21361433 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 110874.

The product of its digits is 1296, while the sum is 23.

The square root of 21361433 is about 4621.8430306535. The cubic root of 21361433 is about 277.4662264446.

Adding to 21361433 its reverse (33416312), we get a palindrome (54777745).

The spelling of 21361433 in words is "twenty-one million, three hundred sixty-one thousand, four hundred thirty-three".