21917041 has 4 divisors (see below), whose sum is σ = 21940452. Its totient is φ = 21893632.

The previous prime is 21917023. The next prime is 21917113. The reversal of 21917041 is 14071912.

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 20214016 + 1703025 = 4496^2 + 1305^2 .

It is a cyclic number.

It is not a de Polignac number, because 21917041 - 2⁹ = 21916529 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21916997 and 21917015.

It is not an unprimeable number, because it can be changed into a prime (21914041) 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, 10240 + ... + 12193.

It is an arithmetic number, because the mean of its divisors is an integer number (5485113).

Almost surely, 2^21917041 is an apocalyptic number.

It is an amenable number.

21917041 is a deficient number, since it is larger than the sum of its proper divisors (23411).

21917041 is an equidigital number, since it uses as much as digits as its factorization.

21917041 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23410.

The product of its (nonzero) digits is 504, while the sum is 25.

The square root of 21917041 is about 4681.5639480840. The cubic root of 21917041 is about 279.8512858245.

Adding to 21917041 its reverse (14071912), we get a palindrome (35988953).

The spelling of 21917041 in words is "twenty-one million, nine hundred seventeen thousand, forty-one".