20487645 has 24 divisors (see below), whose sum is σ = 35651616. Its totient is φ = 10883808.

The previous prime is 20487631. The next prime is 20487667. The reversal of 20487645 is 54678402.

20487645 is a `hidden beast` number, since 2 + 0 + 4 + 8 + 7 + 645 = 666.

It is not a de Polignac number, because 20487645 - 2⁵ = 20487613 is a prime.

It is a plaindrome in base 16.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 13074 + ... + 14556.

It is an arithmetic number, because the mean of its divisors is an integer number (1485484).

Almost surely, 2^20487645 is an apocalyptic number.

It is an amenable number.

20487645 is a deficient number, since it is larger than the sum of its proper divisors (15163971).

20487645 is a wasteful number, since it uses less digits than its factorization.

20487645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1801 (or 1798 counting only the distinct ones).

The product of its (nonzero) digits is 53760, while the sum is 36.

The square root of 20487645 is about 4526.3279819297. The cubic root of 20487645 is about 273.6301908948.

The spelling of 20487645 in words is "twenty million, four hundred eighty-seven thousand, six hundred forty-five".