20906487 has 18 divisors (see below), whose sum is σ = 35129328. Its totient is φ = 11946312.

The previous prime is 20906461. The next prime is 20906489. The reversal of 20906487 is 78460902.

20906487 is a `hidden beast` number, since 2 + 0 + 9 + 0 + 648 + 7 = 666.

It is not a de Polignac number, because 20906487 - 2¹¹ = 20904439 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20906489) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 23263 + ... + 24144.

Almost surely, 2^20906487 is an apocalyptic number.

20906487 is a deficient number, since it is larger than the sum of its proper divisors (14222841).

20906487 is a wasteful number, since it uses less digits than its factorization.

20906487 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 47427 (or 47417 counting only the distinct ones).

The product of its (nonzero) digits is 24192, while the sum is 36.

The square root of 20906487 is about 4572.3612062041. The cubic root of 20906487 is about 275.4822919592.

The spelling of 20906487 in words is "twenty million, nine hundred six thousand, four hundred eighty-seven".