20010217561 has 8 divisors (see below), whose sum is σ = 20042646624. Its totient is φ = 19977816480.

The previous prime is 20010217541. The next prime is 20010217609. The reversal of 20010217561 is 16571201002.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 20010217561 - 2²⁵ = 19976663129 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20010217531) 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, 1769421 + ... + 1780693.

It is an arithmetic number, because the mean of its divisors is an integer number (2505330828).

Almost surely, 2^20010217561 is an apocalyptic number.

It is an amenable number.

20010217561 is a deficient number, since it is larger than the sum of its proper divisors (32429063).

20010217561 is a wasteful number, since it uses less digits than its factorization.

20010217561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13991.

The product of its (nonzero) digits is 840, while the sum is 25.

Adding to 20010217561 its reverse (16571201002), we get a palindrome (36581418563).

The spelling of 20010217561 in words is "twenty billion, ten million, two hundred seventeen thousand, five hundred sixty-one".