21527393 has 2 divisors, whose sum is σ = 21527394. Its totient is φ = 21527392.

The previous prime is 21527351. The next prime is 21527411. The reversal of 21527393 is 39372512.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18258529 + 3268864 = 4273^2 + 1808^2 .

It is a cyclic number.

It is not a de Polignac number, because 21527393 - 2⁶ = 21527329 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (21529393) by changing a digit.

It is a good prime.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10763696 + 10763697.

It is an arithmetic number, because the mean of its divisors is an integer number (10763697).

Almost surely, 2^21527393 is an apocalyptic number.

It is an amenable number.

21527393 is a deficient number, since it is larger than the sum of its proper divisors (1).

21527393 is an equidigital number, since it uses as much as digits as its factorization.

21527393 is an evil number, because the sum of its binary digits is even.

The product of its digits is 11340, while the sum is 32.

The square root of 21527393 is about 4639.7621706290. The cubic root of 21527393 is about 278.1829317189.

The spelling of 21527393 in words is "twenty-one million, five hundred twenty-seven thousand, three hundred ninety-three".