21765341 has 12 divisors (see below), whose sum is σ = 24386580. Its totient is φ = 19393920.

The previous prime is 21765329. The next prime is 21765347. The reversal of 21765341 is 14356712.

It can be written as a sum of positive squares in 6 ways, for example, as 3880900 + 17884441 = 1970^2 + 4229^2 .

It is not a de Polignac number, because 21765341 - 2¹⁸ = 21503197 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (29).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21765347) 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 11 ways as a sum of consecutive naturals, for example, 2681 + ... + 7121.

It is an arithmetic number, because the mean of its divisors is an integer number (2032215).

Almost surely, 2^21765341 is an apocalyptic number.

It is an amenable number.

21765341 is a deficient number, since it is larger than the sum of its proper divisors (2621239).

21765341 is a wasteful number, since it uses less digits than its factorization.

21765341 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4496 (or 4483 counting only the distinct ones).

The product of its digits is 5040, while the sum is 29.

The square root of 21765341 is about 4665.3339644660. Note that the first 3 decimals coincide. The cubic root of 21765341 is about 279.2041217239.

The spelling of 21765341 in words is "twenty-one million, seven hundred sixty-five thousand, three hundred forty-one".