20471587 has 16 divisors (see below), whose sum is σ = 23188032. Its totient is φ = 17966080.

The previous prime is 20471579. The next prime is 20471599. The reversal of 20471587 is 78517402.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 20471587 - 2³ = 20471579 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20471287) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 15393 + ... + 16669.

It is an arithmetic number, because the mean of its divisors is an integer number (1449252).

Almost surely, 2^20471587 is an apocalyptic number.

20471587 is a deficient number, since it is larger than the sum of its proper divisors (2716445).

20471587 is a wasteful number, since it uses less digits than its factorization.

20471587 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1358.

The product of its (nonzero) digits is 15680, while the sum is 34.

The square root of 20471587 is about 4524.5537901543. The cubic root of 20471587 is about 273.5586827236.

Adding to 20471587 its reverse (78517402), we get a palindrome (98988989).

The spelling of 20471587 in words is "twenty million, four hundred seventy-one thousand, five hundred eighty-seven".