21517041 has 32 divisors (see below), whose sum is σ = 35562240. Its totient is φ = 11268864.

The previous prime is 21517039. The next prime is 21517051. The reversal of 21517041 is 14071512.

It is a happy number.

It is not a de Polignac number, because 21517041 - 2¹ = 21517039 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a junction number, because it is equal to n+sod(n) for n = 21516999 and 21517017.

It is not an unprimeable number, because it can be changed into a prime (21517021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 73291 + ... + 73583.

It is an arithmetic number, because the mean of its divisors is an integer number (1111320).

Almost surely, 2^21517041 is an apocalyptic number.

21517041 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

21517041 is a deficient number, since it is larger than the sum of its proper divisors (14045199).

21517041 is a wasteful number, since it uses less digits than its factorization.

21517041 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 585.

The product of its (nonzero) digits is 280, while the sum is 21.

The square root of 21517041 is about 4638.6464620620. The cubic root of 21517041 is about 278.1383340996.

Adding to 21517041 its reverse (14071512), we get a palindrome (35588553).

The spelling of 21517041 in words is "twenty-one million, five hundred seventeen thousand, forty-one".