21524117 has 2 divisors, whose sum is σ = 21524118. Its totient is φ = 21524116.

The previous prime is 21524099. The next prime is 21524171. The reversal of 21524117 is 71142512.

Together with next prime (21524171) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13734436 + 7789681 = 3706^2 + 2791^2 .

It is a cyclic number.

It is not a de Polignac number, because 21524117 - 2¹⁰ = 21523093 is a prime.

It is a super-2 number, since 2×21524117² = 926575225259378, which contains 22 as substring.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 21524092 and 21524101.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21524317) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10762058 + 10762059.

It is an arithmetic number, because the mean of its divisors is an integer number (10762059).

Almost surely, 2^21524117 is an apocalyptic number.

It is an amenable number.

21524117 is a deficient number, since it is larger than the sum of its proper divisors (1).

21524117 is an equidigital number, since it uses as much as digits as its factorization.

21524117 is an evil number, because the sum of its binary digits is even.

The product of its digits is 560, while the sum is 23.

The square root of 21524117 is about 4639.4091218602. The cubic root of 21524117 is about 278.1688198767.

Adding to 21524117 its reverse (71142512), we get a palindrome (92666629).

The spelling of 21524117 in words is "twenty-one million, five hundred twenty-four thousand, one hundred seventeen".