20686523 has 12 divisors (see below), whose sum is σ = 24489024. Its totient is φ = 17358000.

The previous prime is 20686513. The next prime is 20686529. The reversal of 20686523 is 32568602.

It is not a de Polignac number, because 20686523 - 2¹² = 20682427 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 20686523.

It is not an unprimeable number, because it can be changed into a prime (20686529) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5003 + ... + 8148.

It is an arithmetic number, because the mean of its divisors is an integer number (2040752).

Almost surely, 2^20686523 is an apocalyptic number.

20686523 is a deficient number, since it is larger than the sum of its proper divisors (3802501).

20686523 is a wasteful number, since it uses less digits than its factorization.

20686523 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13186 (or 13175 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 32.

The square root of 20686523 is about 4548.2439468437. The cubic root of 20686523 is about 274.5127371460.

The spelling of 20686523 in words is "twenty million, six hundred eighty-six thousand, five hundred twenty-three".