21527249 has 2 divisors, whose sum is σ = 21527250. Its totient is φ = 21527248.

The previous prime is 21527227. The next prime is 21527329. The reversal of 21527249 is 94272512.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20070400 + 1456849 = 4480^2 + 1207^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21527249 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (21527549) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10763624 + 10763625.

It is an arithmetic number, because the mean of its divisors is an integer number (10763625).

Almost surely, 2^21527249 is an apocalyptic number.

It is an amenable number.

21527249 is a deficient number, since it is larger than the sum of its proper divisors (1).

21527249 is an equidigital number, since it uses as much as digits as its factorization.

21527249 is an evil number, because the sum of its binary digits is even.

The product of its digits is 10080, while the sum is 32.

The square root of 21527249 is about 4639.7466525663. The cubic root of 21527249 is about 278.1823114482.

It can be divided in two parts, 2 and 1527249, that added together give a palindrome (1527251).

The spelling of 21527249 in words is "twenty-one million, five hundred twenty-seven thousand, two hundred forty-nine".