21756310201 has 8 divisors (see below), whose sum is σ = 23062988520. Its totient is φ = 20452620288.

The previous prime is 21756310193. The next prime is 21756310211. The reversal of 21756310201 is 10201365712.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 7048442025 + 14707868176 = 83955^2 + 121276^2 .

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 21756310201 - 2³ = 21756310193 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21756310201.

It is not an unprimeable number, because it can be changed into a prime (21756310211) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 732096 + ... + 761233.

It is an arithmetic number, because the mean of its divisors is an integer number (2882873565).

Almost surely, 2^21756310201 is an apocalyptic number.

It is an amenable number.

21756310201 is a deficient number, since it is larger than the sum of its proper divisors (1306678319).

21756310201 is a wasteful number, since it uses less digits than its factorization.

21756310201 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1494203.

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

Adding to 21756310201 its reverse (10201365712), we get a palindrome (31957675913).

The spelling of 21756310201 in words is "twenty-one billion, seven hundred fifty-six million, three hundred ten thousand, two hundred one".