21012117 has 8 divisors (see below), whose sum is σ = 32018496. Its totient is φ = 12006912.

The previous prime is 21012091. The next prime is 21012127. The reversal of 21012117 is 71121012.

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

It is not a de Polignac number, because 21012117 - 2⁶ = 21012053 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21012096 and 21012105.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21012127) 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, 500268 + ... + 500309.

It is an arithmetic number, because the mean of its divisors is an integer number (4002312).

Almost surely, 2^21012117 is an apocalyptic number.

It is an amenable number.

21012117 is a deficient number, since it is larger than the sum of its proper divisors (11006379).

21012117 is a wasteful number, since it uses less digits than its factorization.

21012117 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1000587.

The product of its (nonzero) digits is 28, while the sum is 15.

The square root of 21012117 is about 4583.8975773898. The cubic root of 21012117 is about 275.9454707439.

Adding to 21012117 its reverse (71121012), we get a palindrome (92133129).

The spelling of 21012117 in words is "twenty-one million, twelve thousand, one hundred seventeen".