20284687 has 4 divisors (see below), whose sum is σ = 20430760. Its totient is φ = 20138616.

The previous prime is 20284669. The next prime is 20284697. The reversal of 20284687 is 78648202.

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

It is a cyclic number.

It is not a de Polignac number, because 20284687 - 2⁷ = 20284559 is a prime.

It is a super-2 number, since 2×20284687² = 822937053375938, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20284697) 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, 72828 + ... + 73105.

It is an arithmetic number, because the mean of its divisors is an integer number (5107690).

Almost surely, 2^20284687 is an apocalyptic number.

20284687 is a deficient number, since it is larger than the sum of its proper divisors (146073).

20284687 is a wasteful number, since it uses less digits than its factorization.

20284687 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 146072.

The product of its (nonzero) digits is 43008, while the sum is 37.

The square root of 20284687 is about 4503.8524620596. The cubic root of 20284687 is about 272.7236309177.

The spelling of 20284687 in words is "twenty million, two hundred eighty-four thousand, six hundred eighty-seven".