20671816 has 16 divisors (see below), whose sum is σ = 42283440. Its totient is φ = 9396240.

The previous prime is 20671811. The next prime is 20671817. The reversal of 20671816 is 61817602.

It is not an unprimeable number, because it can be changed into a prime (20671811) 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 3 ways as a sum of consecutive naturals, for example, 117366 + ... + 117541.

It is an arithmetic number, because the mean of its divisors is an integer number (2642715).

Almost surely, 2^20671816 is an apocalyptic number.

It is an amenable number.

20671816 is an abundant number, since it is smaller than the sum of its proper divisors (21611624).

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

20671816 is a wasteful number, since it uses less digits than its factorization.

20671816 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 234924 (or 234920 counting only the distinct ones).

The product of its (nonzero) digits is 4032, while the sum is 31.

The square root of 20671816 is about 4546.6268815464. The cubic root of 20671816 is about 274.4476671491.

It can be divided in two parts, 2067 and 1816, that added together give a palindrome (3883).

The spelling of 20671816 in words is "twenty million, six hundred seventy-one thousand, eight hundred sixteen".