21601563041001 has 16 divisors (see below), whose sum is σ = 31636156400640. Its totient is φ = 13049914513680.

The previous prime is 21601563040999. The next prime is 21601563041021. The reversal of 21601563041001 is 10014036510612.

It is a happy number.

It is not a de Polignac number, because 21601563041001 - 2¹ = 21601563040999 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 21601563041001.

It is not an unprimeable number, because it can be changed into a prime (21601563041021) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8238581085 + ... + 8238583706.

It is an arithmetic number, because the mean of its divisors is an integer number (1977259775040).

Almost surely, 2^{21601563041001} is an apocalyptic number.

It is an amenable number.

21601563041001 is a deficient number, since it is larger than the sum of its proper divisors (10034593359639).

21601563041001 is a wasteful number, since it uses less digits than its factorization.

21601563041001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16477164836.

The product of its (nonzero) digits is 4320, while the sum is 30.

Adding to 21601563041001 its reverse (10014036510612), we get a palindrome (31615599551613).

The spelling of 21601563041001 in words is "twenty-one trillion, six hundred one billion, five hundred sixty-three million, forty-one thousand, one".