20487197 has 4 divisors (see below), whose sum is σ = 20561436. Its totient is φ = 20412960.

The previous prime is 20487163. The next prime is 20487211. The reversal of 20487197 is 79178402.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 11600836 + 8886361 = 3406^2 + 2981^2 .

It is a cyclic number.

It is not a de Polignac number, because 20487197 - 2¹² = 20483101 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20487197.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20487107) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 36704 + ... + 37257.

It is an arithmetic number, because the mean of its divisors is an integer number (5140359).

Almost surely, 2^20487197 is an apocalyptic number.

It is an amenable number.

20487197 is a deficient number, since it is larger than the sum of its proper divisors (74239).

20487197 is an equidigital number, since it uses as much as digits as its factorization.

20487197 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 74238.

The product of its (nonzero) digits is 28224, while the sum is 38.

The square root of 20487197 is about 4526.2784934204. The cubic root of 20487197 is about 273.6281964047.

The spelling of 20487197 in words is "twenty million, four hundred eighty-seven thousand, one hundred ninety-seven".