21465523 has 2 divisors, whose sum is σ = 21465524. Its totient is φ = 21465522.

The previous prime is 21465517. The next prime is 21465541. The reversal of 21465523 is 32556412.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21465523 - 2¹⁷ = 21334451 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21465491 and 21465500.

It is not a weakly prime, because it can be changed into another prime (21465503) 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 as a sum of consecutive naturals, namely, 10732761 + 10732762.

It is an arithmetic number, because the mean of its divisors is an integer number (10732762).

Almost surely, 2^21465523 is an apocalyptic number.

21465523 is a deficient number, since it is larger than the sum of its proper divisors (1).

21465523 is an equidigital number, since it uses as much as digits as its factorization.

21465523 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 7200, while the sum is 28.

The square root of 21465523 is about 4633.0900056010. The cubic root of 21465523 is about 277.9161755795.

The spelling of 21465523 in words is "twenty-one million, four hundred sixty-five thousand, five hundred twenty-three".