20717986 has 8 divisors (see below), whose sum is σ = 32428224. Its totient is φ = 9908580.

The previous prime is 20717969. The next prime is 20717989. The reversal of 20717986 is 68971702.

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

It is not an unprimeable number, because it can be changed into a prime (20717989) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 225150 + ... + 225241.

It is an arithmetic number, because the mean of its divisors is an integer number (4053528).

Almost surely, 2^20717986 is an apocalyptic number.

20717986 is a deficient number, since it is larger than the sum of its proper divisors (11710238).

20717986 is a wasteful number, since it uses less digits than its factorization.

20717986 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 450416.

The product of its (nonzero) digits is 42336, while the sum is 40.

The square root of 20717986 is about 4551.7014401210. The cubic root of 20717986 is about 274.6518392908.

The spelling of 20717986 in words is "twenty million, seven hundred seventeen thousand, nine hundred eighty-six".