20711897 has 4 divisors (see below), whose sum is σ = 21271716. Its totient is φ = 20152080.

The previous prime is 20711893. The next prime is 20711909. The reversal of 20711897 is 79811702.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 18139081 + 2572816 = 4259^2 + 1604^2 .

It is a cyclic number.

It is not a de Polignac number, because 20711897 - 2² = 20711893 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20711893) 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, 279854 + ... + 279927.

It is an arithmetic number, because the mean of its divisors is an integer number (5317929).

Almost surely, 2^20711897 is an apocalyptic number.

It is an amenable number.

20711897 is a deficient number, since it is larger than the sum of its proper divisors (559819).

20711897 is an equidigital number, since it uses as much as digits as its factorization.

20711897 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 559818.

The product of its (nonzero) digits is 7056, while the sum is 35.

The square root of 20711897 is about 4551.0325202090. The cubic root of 20711897 is about 274.6249300003.

The spelling of 20711897 in words is "twenty million, seven hundred eleven thousand, eight hundred ninety-seven".