21717027 has 12 divisors (see below), whose sum is σ = 32451120. Its totient is φ = 13978608.

The previous prime is 21717013. The next prime is 21717029. The reversal of 21717027 is 72071712.

It is not a de Polignac number, because 21717027 - 2⁶ = 21716963 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21717029) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 41343 + ... + 41864.

It is an arithmetic number, because the mean of its divisors is an integer number (2704260).

Almost surely, 2^21717027 is an apocalyptic number.

21717027 is a deficient number, since it is larger than the sum of its proper divisors (10734093).

21717027 is a wasteful number, since it uses less digits than its factorization.

21717027 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 83242 (or 83239 counting only the distinct ones).

The product of its (nonzero) digits is 1372, while the sum is 27.

The square root of 21717027 is about 4660.1531090727. The cubic root of 21717027 is about 278.9973792485.

Adding to 21717027 its reverse (72071712), we get a palindrome (93788739).

The spelling of 21717027 in words is "twenty-one million, seven hundred seventeen thousand, twenty-seven".