20717130 has 64 divisors (see below), whose sum is σ = 58060800. Its totient is φ = 4632384.

The previous prime is 20717119. The next prime is 20717131. The reversal of 20717130 is 3171702.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a junction number, because it is equal to n+sod(n) for n = 20717097 and 20717106.

It is not an unprimeable number, because it can be changed into a prime (20717131) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 8821 + ... + 10919.

It is an arithmetic number, because the mean of its divisors is an integer number (907200).

Almost surely, 2^20717130 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20717130, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29030400).

20717130 is an abundant number, since it is smaller than the sum of its proper divisors (37343670).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20717130 is a wasteful number, since it uses less digits than its factorization.

20717130 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2163.

The product of its (nonzero) digits is 294, while the sum is 21.

The square root of 20717130 is about 4551.6074083778. The cubic root of 20717130 is about 274.6480566642.

Adding to 20717130 its reverse (3171702), we get a palindrome (23888832).

The spelling of 20717130 in words is "twenty million, seven hundred seventeen thousand, one hundred thirty".