20730287 has 4 divisors (see below), whose sum is σ = 20924136. Its totient is φ = 20536440.

The previous prime is 20730277. The next prime is 20730313. The reversal of 20730287 is 78203702.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 78203702 = 2 ⋅39101851.

It is a cyclic number.

It is not a de Polignac number, because 20730287 - 2⁴ = 20730271 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20730217) 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, 96764 + ... + 96977.

It is an arithmetic number, because the mean of its divisors is an integer number (5231034).

Almost surely, 2^20730287 is an apocalyptic number.

20730287 is a deficient number, since it is larger than the sum of its proper divisors (193849).

20730287 is a wasteful number, since it uses less digits than its factorization.

20730287 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 193848.

The product of its (nonzero) digits is 4704, while the sum is 29.

The square root of 20730287 is about 4553.0524925593. The cubic root of 20730287 is about 274.7061853689.

Adding to 20730287 its reverse (78203702), we get a palindrome (98933989).

The spelling of 20730287 in words is "twenty million, seven hundred thirty thousand, two hundred eighty-seven".