21085526 has 32 divisors (see below), whose sum is σ = 41154048. Its totient is φ = 7856640.

The previous prime is 21085511. The next prime is 21085529. The reversal of 21085526 is 62558012.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21085529) 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 in 15 ways as a sum of consecutive naturals, for example, 566 + ... + 6518.

It is an arithmetic number, because the mean of its divisors is an integer number (1286064).

Almost surely, 2^21085526 is an apocalyptic number.

21085526 is a deficient number, since it is larger than the sum of its proper divisors (20068522).

21085526 is a wasteful number, since it uses less digits than its factorization.

21085526 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5996.

The product of its (nonzero) digits is 4800, while the sum is 29.

The square root of 21085526 is about 4591.8978647178. The cubic root of 21085526 is about 276.2664496118.

The spelling of 21085526 in words is "twenty-one million, eighty-five thousand, five hundred twenty-six".