20420487 has 6 divisors (see below), whose sum is σ = 29496272. Its totient is φ = 13613652.

The previous prime is 20420479. The next prime is 20420503. The reversal of 20420487 is 78402402.

It is not a de Polignac number, because 20420487 - 2³ = 20420479 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 20420487.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20420287) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1134463 + ... + 1134480.

Almost surely, 2^20420487 is an apocalyptic number.

20420487 is a deficient number, since it is larger than the sum of its proper divisors (9075785).

20420487 is a wasteful number, since it uses less digits than its factorization.

20420487 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2268949 (or 2268946 counting only the distinct ones).

The product of its (nonzero) digits is 3584, while the sum is 27.

The square root of 20420487 is about 4518.9032961549. The cubic root of 20420487 is about 273.3308792496.

Adding to 20420487 its reverse (78402402), we get a palindrome (98822889).

The spelling of 20420487 in words is "twenty million, four hundred twenty thousand, four hundred eighty-seven".