21441365 has 16 divisors (see below), whose sum is σ = 28365120. Its totient is φ = 15429120.

The previous prime is 21441347. The next prime is 21441373. The reversal of 21441365 is 56314412.

It is not a de Polignac number, because 21441365 - 2¹⁶ = 21375829 is a prime.

It is a congruent number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 3326 + ... + 7344.

It is an arithmetic number, because the mean of its divisors is an integer number (1772820).

Almost surely, 2^21441365 is an apocalyptic number.

It is an amenable number.

21441365 is a deficient number, since it is larger than the sum of its proper divisors (6923755).

21441365 is a wasteful number, since it uses less digits than its factorization.

21441365 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4132.

The product of its digits is 2880, while the sum is 26.

The square root of 21441365 is about 4630.4821563202. The cubic root of 21441365 is about 277.8118777989.

Adding to 21441365 its reverse (56314412), we get a palindrome (77755777).

It can be divided in two parts, 21 and 441365, that multiplied together give a triangular number (9268665 = T₄₃₀₅).

The spelling of 21441365 in words is "twenty-one million, four hundred forty-one thousand, three hundred sixty-five".