21316527 has 10 divisors (see below), whose sum is σ = 31843328. Its totient is φ = 14210964.

The previous prime is 21316513. The next prime is 21316531. The reversal of 21316527 is 72561312.

It is a happy number.

21316527 is a `hidden beast` number, since 2 + 1 + 3 + 1 + 652 + 7 = 666.

It is not a de Polignac number, because 21316527 - 2¹⁴ = 21300143 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21316527.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21316507) 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 9 ways as a sum of consecutive naturals, for example, 131503 + ... + 131664.

Almost surely, 2^21316527 is an apocalyptic number.

21316527 is a gapful number since it is divisible by the number (27) formed by its first and last digit.

21316527 is a deficient number, since it is larger than the sum of its proper divisors (10526801).

21316527 is an equidigital number, since it uses as much as digits as its factorization.

21316527 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 263179 (or 263170 counting only the distinct ones).

The product of its digits is 2520, while the sum is 27.

The square root of 21316527 is about 4616.9824561070. The cubic root of 21316527 is about 277.2716602273.

Adding to 21316527 its reverse (72561312), we get a palindrome (93877839).

The spelling of 21316527 in words is "twenty-one million, three hundred sixteen thousand, five hundred twenty-seven".