20616571 has 4 divisors (see below), whose sum is σ = 20632392. Its totient is φ = 20600752.

The previous prime is 20616569. The next prime is 20616601. The reversal of 20616571 is 17561602.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 20616571 - 2¹ = 20616569 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20616521) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5761 + ... + 8626.

It is an arithmetic number, because the mean of its divisors is an integer number (5158098).

Almost surely, 2^20616571 is an apocalyptic number.

20616571 is a deficient number, since it is larger than the sum of its proper divisors (15821).

20616571 is a wasteful number, since it uses less digits than its factorization.

20616571 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15820.

The product of its (nonzero) digits is 2520, while the sum is 28.

The square root of 20616571 is about 4540.5474339555. The cubic root of 20616571 is about 274.2029637963.

The spelling of 20616571 in words is "twenty million, six hundred sixteen thousand, five hundred seventy-one".