20217816 has 32 divisors (see below), whose sum is σ = 56161200. Its totient is φ = 6739200.

The previous prime is 20217793. The next prime is 20217817. The reversal of 20217816 is 61871202.

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

It is a self number, because there is not a number n which added to its sum of digits gives 20217816.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20217817) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 46585 + ... + 47016.

Almost surely, 2^20217816 is an apocalyptic number.

It is an amenable number.

20217816 is an abundant number, since it is smaller than the sum of its proper divisors (35943384).

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

20217816 is a wasteful number, since it uses less digits than its factorization.

20217816 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 93616 (or 93606 counting only the distinct ones).

The product of its (nonzero) digits is 1344, while the sum is 27.

The square root of 20217816 is about 4496.4225780058. The cubic root of 20217816 is about 272.4236118406.

The spelling of 20217816 in words is "twenty million, two hundred seventeen thousand, eight hundred sixteen".