20787863605 has 8 divisors (see below), whose sum is σ = 25174294200. Its totient is φ = 16477718976.

The previous prime is 20787863599. The next prime is 20787863609. The reversal of 20787863605 is 50636878702.

It can be written as a sum of positive squares in 4 ways, for example, as 45239076 + 20742624529 = 6726^2 + 144023^2 .

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 20787863605 - 2³ = 20787863597 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20787863609) 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, 19070890 + ... + 19071979.

It is an arithmetic number, because the mean of its divisors is an integer number (3146786775).

Almost surely, 2^20787863605 is an apocalyptic number.

It is an amenable number.

20787863605 is a deficient number, since it is larger than the sum of its proper divisors (4386430595).

20787863605 is a wasteful number, since it uses less digits than its factorization.

20787863605 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38142983.

The product of its (nonzero) digits is 3386880, while the sum is 52.

The spelling of 20787863605 in words is "twenty billion, seven hundred eighty-seven million, eight hundred sixty-three thousand, six hundred five".