20387845 has 8 divisors (see below), whose sum is σ = 25904664. Its totient is φ = 15350784.

The previous prime is 20387837. The next prime is 20387849. The reversal of 20387845 is 54878302.

It can be written as a sum of positive squares in 4 ways, for example, as 1185921 + 19201924 = 1089^2 + 4382^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 20387845 - 2³ = 20387837 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20387849) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 119844 + ... + 120013.

It is an arithmetic number, because the mean of its divisors is an integer number (3238083).

Almost surely, 2^20387845 is an apocalyptic number.

It is an amenable number.

20387845 is a deficient number, since it is larger than the sum of its proper divisors (5516819).

20387845 is a wasteful number, since it uses less digits than its factorization.

20387845 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 239879.

The product of its (nonzero) digits is 53760, while the sum is 37.

The square root of 20387845 is about 4515.2901346425. The cubic root of 20387845 is about 273.1851624385.

The spelling of 20387845 in words is "twenty million, three hundred eighty-seven thousand, eight hundred forty-five".