15601244221 has 2 divisors, whose sum is σ = 15601244222. Its totient is φ = 15601244220.

The previous prime is 15601244207. The next prime is 15601244227. The reversal of 15601244221 is 12244210651.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13027711321 + 2573532900 = 114139^2 + 50730^2 .

It is a cyclic number.

It is not a de Polignac number, because 15601244221 - 2²³ = 15592855613 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 15601244221.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (15601244227) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7800622110 + 7800622111.

It is an arithmetic number, because the mean of its divisors is an integer number (7800622111).

Almost surely, 2^15601244221 is an apocalyptic number.

It is an amenable number.

15601244221 is a deficient number, since it is larger than the sum of its proper divisors (1).

15601244221 is an equidigital number, since it uses as much as digits as its factorization.

15601244221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3840, while the sum is 28.

Adding to 15601244221 its reverse (12244210651), we get a palindrome (27845454872).

The spelling of 15601244221 in words is "fifteen billion, six hundred one million, two hundred forty-four thousand, two hundred twenty-one".