21112550 has 48 divisors (see below), whose sum is σ = 41461632. Its totient is φ = 7987200.

The previous prime is 21112547. The next prime is 21112561. The reversal of 21112550 is 5521112.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

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 23 ways as a sum of consecutive naturals, for example, 82022 + ... + 82278.

It is an arithmetic number, because the mean of its divisors is an integer number (863784).

Almost surely, 2^21112550 is an apocalyptic number.

21112550 is a deficient number, since it is larger than the sum of its proper divisors (20349082).

21112550 is a wasteful number, since it uses less digits than its factorization.

21112550 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 353 (or 348 counting only the distinct ones).

The product of its (nonzero) digits is 100, while the sum is 17.

The square root of 21112550 is about 4594.8394966527. The cubic root of 21112550 is about 276.3844237032.

Adding to 21112550 its reverse (5521112), we get a palindrome (26633662).

The spelling of 21112550 in words is "twenty-one million, one hundred twelve thousand, five hundred fifty".