20816385 has 16 divisors (see below), whose sum is σ = 34207296. Its totient is φ = 10801728.

The previous prime is 20816371. The next prime is 20816387. The reversal of 20816385 is 58361802.

It is a happy number.

It is not a de Polignac number, because 20816385 - 2⁸ = 20816129 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20816387) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 18199 + ... + 19308.

It is an arithmetic number, because the mean of its divisors is an integer number (2137956).

Almost surely, 2^20816385 is an apocalyptic number.

It is an amenable number.

20816385 is a deficient number, since it is larger than the sum of its proper divisors (13390911).

20816385 is a wasteful number, since it uses less digits than its factorization.

20816385 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 37552.

The product of its (nonzero) digits is 11520, while the sum is 33.

The square root of 20816385 is about 4562.4976712323. The cubic root of 20816385 is about 275.0859676133.

The spelling of 20816385 in words is "twenty million, eight hundred sixteen thousand, three hundred eighty-five".