20717042 has 4 divisors (see below), whose sum is σ = 31075566. Its totient is φ = 10358520.

The previous prime is 20717041. The next prime is 20717057. The reversal of 20717042 is 24071702.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 24071702 = 2 ⋅12035851.

It can be written as a sum of positive squares in only one way, i.e., 14371681 + 6345361 = 3791^2 + 2519^2 .

It is a junction number, because it is equal to n+sod(n) for n = 20716999 and 20717017.

It is not an unprimeable number, because it can be changed into a prime (20717041) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5179259 + ... + 5179262.

Almost surely, 2^20717042 is an apocalyptic number.

20717042 is a deficient number, since it is larger than the sum of its proper divisors (10358524).

20717042 is a wasteful number, since it uses less digits than its factorization.

20717042 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10358523.

The product of its (nonzero) digits is 784, while the sum is 23.

The square root of 20717042 is about 4551.5977414530. The cubic root of 20717042 is about 274.6476677902.

Adding to 20717042 its reverse (24071702), we get a palindrome (44788744).

The spelling of 20717042 in words is "twenty million, seven hundred seventeen thousand, forty-two".