21313527 has 4 divisors (see below), whose sum is σ = 28418040. Its totient is φ = 14209016.

The previous prime is 21313493. The next prime is 21313531. The reversal of 21313527 is 72531312.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21313527 - 2¹⁶ = 21247991 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21313497 and 21313506.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21313547) 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, 3552252 + ... + 3552257.

It is an arithmetic number, because the mean of its divisors is an integer number (7104510).

Almost surely, 2^21313527 is an apocalyptic number.

21313527 is a deficient number, since it is larger than the sum of its proper divisors (7104513).

21313527 is an equidigital number, since it uses as much as digits as its factorization.

21313527 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7104512.

The product of its digits is 1260, while the sum is 24.

The square root of 21313527 is about 4616.6575571511. The cubic root of 21313527 is about 277.2586522609.

Adding to 21313527 its reverse (72531312), we get a palindrome (93844839).

The spelling of 21313527 in words is "twenty-one million, three hundred thirteen thousand, five hundred twenty-seven".