20387305 has 16 divisors (see below), whose sum is σ = 25519104. Its totient is φ = 15618240.

The previous prime is 20387287. The next prime is 20387357. The reversal of 20387305 is 50378302.

20387305 is a nontrivial binomial coefficient, being equal to C(6386, 2).

It is not a de Polignac number, because 20387305 - 2¹¹ = 20385257 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 15327 + ... + 16603.

It is an arithmetic number, because the mean of its divisors is an integer number (1594944).

Almost surely, 2^20387305 is an apocalyptic number.

20387305 is the 6385-th triangular number and also the 3193-rd hexagonal number.

20387305 is the 2129-th centered nonagonal number.

It is an amenable number.

20387305 is a deficient number, since it is larger than the sum of its proper divisors (5131799).

20387305 is a wasteful number, since it uses less digits than its factorization.

20387305 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1416.

The product of its (nonzero) digits is 5040, while the sum is 28.

The square root of 20387305 is about 4515.2303374247. The cubic root of 20387305 is about 273.1827505228.

The spelling of 20387305 in words is "twenty million, three hundred eighty-seven thousand, three hundred five".