21240527 has 16 divisors (see below), whose sum is σ = 26621952. Its totient is φ = 16463520.

The previous prime is 21240517. The next prime is 21240529. The reversal of 21240527 is 72504212.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 21240527 - 2⁴ = 21240511 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21240529) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 16553 + ... + 17789.

It is an arithmetic number, because the mean of its divisors is an integer number (1663872).

Almost surely, 2^21240527 is an apocalyptic number.

21240527 is a deficient number, since it is larger than the sum of its proper divisors (5381425).

21240527 is a wasteful number, since it uses less digits than its factorization.

21240527 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1478.

The product of its (nonzero) digits is 1120, while the sum is 23.

The square root of 21240527 is about 4608.7446229966. The cubic root of 21240527 is about 276.9417481456.

Adding to 21240527 its reverse (72504212), we get a palindrome (93744739).

The spelling of 21240527 in words is "twenty-one million, two hundred forty thousand, five hundred twenty-seven".