21532519 has 2 divisors, whose sum is σ = 21532520. Its totient is φ = 21532518.

The previous prime is 21532517. The next prime is 21532541. The reversal of 21532519 is 91523512.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21532519 - 2¹ = 21532517 is a prime.

It is a super-2 number, since 2×21532519² = 927298748970722, which contains 22 as substring.

Together with 21532517, it forms a pair of twin primes.

It is a plaindrome in base 11.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21532513) 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, 10766259 + 10766260.

It is an arithmetic number, because the mean of its divisors is an integer number (10766260).

Almost surely, 2^21532519 is an apocalyptic number.

21532519 is a deficient number, since it is larger than the sum of its proper divisors (1).

21532519 is an equidigital number, since it uses as much as digits as its factorization.

21532519 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2700, while the sum is 28.

The square root of 21532519 is about 4640.3145367529. The cubic root of 21532519 is about 278.2050098303.

The spelling of 21532519 in words is "twenty-one million, five hundred thirty-two thousand, five hundred nineteen".