20216685 has 16 divisors (see below), whose sum is σ = 32411520. Its totient is φ = 10760640.

The previous prime is 20216659. The next prime is 20216699. The reversal of 20216685 is 58661202.

It is not a de Polignac number, because 20216685 - 2¹⁰ = 20215661 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8896 + ... + 10934.

It is an arithmetic number, because the mean of its divisors is an integer number (2025720).

Almost surely, 2^20216685 is an apocalyptic number.

It is an amenable number.

20216685 is a deficient number, since it is larger than the sum of its proper divisors (12194835).

20216685 is a wasteful number, since it uses less digits than its factorization.

20216685 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2708.

The product of its (nonzero) digits is 5760, while the sum is 30.

The square root of 20216685 is about 4496.2968095979. The cubic root of 20216685 is about 272.4185318845.

Adding to 20216685 its reverse (58661202), we get a palindrome (78877887).

The spelling of 20216685 in words is "twenty million, two hundred sixteen thousand, six hundred eighty-five".