20471616 has 140 divisors (see below), whose sum is σ = 66385440. Its totient is φ = 6186240.

The previous prime is 20471603. The next prime is 20471639. The reversal of 20471616 is 61617402.

20471616 is a `hidden beast` number, since 2 + 0 + 47 + 1 + 616 = 666.

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 20471616.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 56845 + ... + 57203.

Almost surely, 2^20471616 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20471616, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33192720).

20471616 is an abundant number, since it is smaller than the sum of its proper divisors (45913824).

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

20471616 is a wasteful number, since it uses less digits than its factorization.

20471616 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 394 (or 375 counting only the distinct ones).

The product of its (nonzero) digits is 2016, while the sum is 27.

The square root of 20471616 is about 4524.5569948891. The cubic root of 20471616 is about 273.5588118977.

It can be divided in two parts, 2047 and 1616, that added together give a palindrome (3663).

The spelling of 20471616 in words is "twenty million, four hundred seventy-one thousand, six hundred sixteen".