20687130 has 64 divisors (see below), whose sum is σ = 58423680. Its totient is φ = 5190912.

The previous prime is 20687129. The next prime is 20687131. The reversal of 20687130 is 3178602.

It is an interprime number because it is at equal distance from previous prime (20687129) and next prime (20687131).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 20687094 and 20687103.

It is not an unprimeable number, because it can be changed into a prime (20687131) 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 31 ways as a sum of consecutive naturals, for example, 2337 + ... + 6843.

It is an arithmetic number, because the mean of its divisors is an integer number (912870).

Almost surely, 2^20687130 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20687130, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29211840).

20687130 is an abundant number, since it is smaller than the sum of its proper divisors (37736550).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20687130 is a wasteful number, since it uses less digits than its factorization.

20687130 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4540 (or 4534 counting only the distinct ones).

The product of its (nonzero) digits is 2016, while the sum is 27.

The square root of 20687130 is about 4548.3106754047. The cubic root of 20687130 is about 274.5154221082.

The spelling of 20687130 in words is "twenty million, six hundred eighty-seven thousand, one hundred thirty".