21523522 has 8 divisors (see below), whose sum is σ = 32521356. Its totient is φ = 10683072.

The previous prime is 21523519. The next prime is 21523531. The reversal of 21523522 is 22532512.

It can be written as a sum of positive squares in 2 ways, for example, as 20802721 + 720801 = 4561^2 + 849^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a junction number, because it is equal to n+sod(n) for n = 21523493 and 21523502.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 39003 + ... + 39550.

Almost surely, 2^21523522 is an apocalyptic number.

21523522 is a deficient number, since it is larger than the sum of its proper divisors (10997834).

21523522 is a wasteful number, since it uses less digits than its factorization.

21523522 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 78692.

The product of its digits is 1200, while the sum is 22.

The square root of 21523522 is about 4639.3449968719. The cubic root of 21523522 is about 278.1662566748.

The spelling of 21523522 in words is "twenty-one million, five hundred twenty-three thousand, five hundred twenty-two".