20685715201 has 4 divisors (see below), whose sum is σ = 20686014400. Its totient is φ = 20685416004.

The previous prime is 20685715159. The next prime is 20685715217. The reversal of 20685715201 is 10251758602.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20685715201 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20685715231) 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, 13060 + ... + 203818.

It is an arithmetic number, because the mean of its divisors is an integer number (5171503600).

Almost surely, 2^20685715201 is an apocalyptic number.

It is an amenable number.

20685715201 is a deficient number, since it is larger than the sum of its proper divisors (299199).

20685715201 is a wasteful number, since it uses less digits than its factorization.

20685715201 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 299198.

The product of its (nonzero) digits is 33600, while the sum is 37.

The spelling of 20685715201 in words is "twenty billion, six hundred eighty-five million, seven hundred fifteen thousand, two hundred one".