20487745 has 16 divisors (see below), whose sum is σ = 25597440. Its totient is φ = 15724800.

The previous prime is 20487743. The next prime is 20487763. The reversal of 20487745 is 54778402.

It is not a de Polignac number, because 20487745 - 2¹ = 20487743 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20487743) 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 15 ways as a sum of consecutive naturals, for example, 19801 + ... + 20809.

It is an arithmetic number, because the mean of its divisors is an integer number (1599840).

Almost surely, 2^20487745 is an apocalyptic number.

It is an amenable number.

20487745 is a deficient number, since it is larger than the sum of its proper divisors (5109695).

20487745 is a wasteful number, since it uses less digits than its factorization.

20487745 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1176.

The product of its (nonzero) digits is 62720, while the sum is 37.

The square root of 20487745 is about 4526.3390283981. The cubic root of 20487745 is about 273.6306360896.

The spelling of 20487745 in words is "twenty million, four hundred eighty-seven thousand, seven hundred forty-five".