20687506 has 12 divisors (see below), whose sum is σ = 36097758. Its totient is φ = 8866032.

The previous prime is 20687503. The next prime is 20687507. The reversal of 20687506 is 60578602.

It can be written as a sum of positive squares in only one way, i.e., 17935225 + 2752281 = 4235^2 + 1659^2 .

It is not an unprimeable number, because it can be changed into a prime (20687503) 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 5 ways as a sum of consecutive naturals, for example, 105451 + ... + 105646.

Almost surely, 2^20687506 is an apocalyptic number.

20687506 is a deficient number, since it is larger than the sum of its proper divisors (15410252).

20687506 is a wasteful number, since it uses less digits than its factorization.

20687506 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 211113 (or 211106 counting only the distinct ones).

The product of its (nonzero) digits is 20160, while the sum is 34.

The square root of 20687506 is about 4548.3520092447. The cubic root of 20687506 is about 274.5170852546.

The spelling of 20687506 in words is "twenty million, six hundred eighty-seven thousand, five hundred six".