20171487 has 16 divisors (see below), whose sum is σ = 31366400. Its totient is φ = 11525976.

The previous prime is 20171477. The next prime is 20171491. The reversal of 20171487 is 78417102.

It is not a de Polignac number, because 20171487 - 2⁶ = 20171423 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 (20171477) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8773 + ... + 10830.

It is an arithmetic number, because the mean of its divisors is an integer number (1960400).

Almost surely, 2^20171487 is an apocalyptic number.

20171487 is a deficient number, since it is larger than the sum of its proper divisors (11194913).

20171487 is an equidigital number, since it uses as much as digits as its factorization.

20171487 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19627 (or 19613 counting only the distinct ones).

The product of its (nonzero) digits is 3136, while the sum is 30.

The square root of 20171487 is about 4491.2678610833. The cubic root of 20171487 is about 272.2153670231.

Adding to 20171487 its reverse (78417102), we get a palindrome (98588589).

The spelling of 20171487 in words is "twenty million, one hundred seventy-one thousand, four hundred eighty-seven".