20287697 has 4 divisors (see below), whose sum is σ = 20417076. Its totient is φ = 20158320.

The previous prime is 20287637. The next prime is 20287703. The reversal of 20287697 is 79678202.

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 5779216 + 14508481 = 2404^2 + 3809^2 .

It is a cyclic number.

It is not a de Polignac number, because 20287697 - 2¹⁶ = 20222161 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20287637) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 64454 + ... + 64767.

It is an arithmetic number, because the mean of its divisors is an integer number (5104269).

Almost surely, 2^20287697 is an apocalyptic number.

It is an amenable number.

20287697 is a deficient number, since it is larger than the sum of its proper divisors (129379).

20287697 is a wasteful number, since it uses less digits than its factorization.

20287697 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 129378.

The product of its (nonzero) digits is 84672, while the sum is 41.

The square root of 20287697 is about 4504.1866080348. The cubic root of 20287697 is about 272.7371198700.

The spelling of 20287697 in words is "twenty million, two hundred eighty-seven thousand, six hundred ninety-seven".