21112647 has 8 divisors (see below), whose sum is σ = 28216944. Its totient is φ = 14041728.

The previous prime is 21112639. The next prime is 21112673. The reversal of 21112647 is 74621112.

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

It is not a de Polignac number, because 21112647 - 2³ = 21112639 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21112547) 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 7 ways as a sum of consecutive naturals, for example, 6828 + ... + 9425.

It is an arithmetic number, because the mean of its divisors is an integer number (3527118).

Almost surely, 2^21112647 is an apocalyptic number.

21112647 is a deficient number, since it is larger than the sum of its proper divisors (7104297).

21112647 is a wasteful number, since it uses less digits than its factorization.

21112647 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16689.

The product of its digits is 672, while the sum is 24.

The square root of 21112647 is about 4594.8500519603. The cubic root of 21112647 is about 276.3848469782.

Adding to 21112647 its reverse (74621112), we get a palindrome (95733759).

The spelling of 21112647 in words is "twenty-one million, one hundred twelve thousand, six hundred forty-seven".