21704141 has 4 divisors (see below), whose sum is σ = 22001532. Its totient is φ = 21406752.

The previous prime is 21704131. The next prime is 21704143. The reversal of 21704141 is 14140712.

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 5982916 + 15721225 = 2446^2 + 3965^2 .

It is a cyclic number.

It is not a de Polignac number, because 21704141 - 2⁶ = 21704077 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21704143) 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, 148586 + ... + 148731.

It is an arithmetic number, because the mean of its divisors is an integer number (5500383).

Almost surely, 2^21704141 is an apocalyptic number.

It is an amenable number.

21704141 is a deficient number, since it is larger than the sum of its proper divisors (297391).

21704141 is an equidigital number, since it uses as much as digits as its factorization.

21704141 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 297390.

The product of its (nonzero) digits is 224, while the sum is 20.

The square root of 21704141 is about 4658.7703313213. The cubic root of 21704141 is about 278.9421864339.

Adding to 21704141 its reverse (14140712), we get a palindrome (35844853).

The spelling of 21704141 in words is "twenty-one million, seven hundred four thousand, one hundred forty-one".