20716257 has 8 divisors (see below), whose sum is σ = 28090080. Its totient is φ = 13576640.

The previous prime is 20716253. The next prime is 20716273. The reversal of 20716257 is 75261702.

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

It is a cyclic number.

It is not a de Polignac number, because 20716257 - 2² = 20716253 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20716253) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 58344 + ... + 58697.

It is an arithmetic number, because the mean of its divisors is an integer number (3511260).

Almost surely, 2^20716257 is an apocalyptic number.

It is an amenable number.

20716257 is a deficient number, since it is larger than the sum of its proper divisors (7373823).

20716257 is a wasteful number, since it uses less digits than its factorization.

20716257 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 117103.

The product of its (nonzero) digits is 5880, while the sum is 30.

The square root of 20716257 is about 4551.5115071809. The cubic root of 20716257 is about 274.6441988081.

Adding to 20716257 its reverse (75261702), we get a palindrome (95977959).

The spelling of 20716257 in words is "twenty million, seven hundred sixteen thousand, two hundred fifty-seven".