21522519 has 12 divisors (see below), whose sum is σ = 31132816. Its totient is φ = 14327712.

The previous prime is 21522511. The next prime is 21522521. The reversal of 21522519 is 91522512.

It is not a de Polignac number, because 21522519 - 2³ = 21522511 is a prime.

It is a super-2 number, since 2×21522519² = 926437648210722, which contains 22 as substring.

It is a Duffinian number.

It is a nialpdrome in base 9.

It is a junction number, because it is equal to n+sod(n) for n = 21522492 and 21522501.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21522511) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 7467 + ... + 9939.

Almost surely, 2^21522519 is an apocalyptic number.

21522519 is a deficient number, since it is larger than the sum of its proper divisors (9610297).

21522519 is a wasteful number, since it uses less digits than its factorization.

21522519 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3446 (or 3443 counting only the distinct ones).

The product of its digits is 1800, while the sum is 27.

The square root of 21522519 is about 4639.2368984565. The cubic root of 21522519 is about 278.1619357418.

The spelling of 21522519 in words is "twenty-one million, five hundred twenty-two thousand, five hundred nineteen".