21441515250161 has 2 divisors, whose sum is σ = 21441515250162. Its totient is φ = 21441515250160.

The previous prime is 21441515250131. The next prime is 21441515250241. The reversal of 21441515250161 is 16105251514412.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20630490726400 + 811024523761 = 4542080^2 + 900569^2 .

It is a cyclic number.

It is not a de Polignac number, because 21441515250161 - 2¹⁰ = 21441515249137 is a prime.

It is not a weakly prime, because it can be changed into another prime (21441515250101) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10720757625080 + 10720757625081.

It is an arithmetic number, because the mean of its divisors is an integer number (10720757625081).

Almost surely, 2^{21441515250161} is an apocalyptic number.

It is an amenable number.

21441515250161 is a deficient number, since it is larger than the sum of its proper divisors (1).

21441515250161 is an equidigital number, since it uses as much as digits as its factorization.

21441515250161 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 48000, while the sum is 38.

Adding to 21441515250161 its reverse (16105251514412), we get a palindrome (37546766764573).

The spelling of 21441515250161 in words is "twenty-one trillion, four hundred forty-one billion, five hundred fifteen million, two hundred fifty thousand, one hundred sixty-one".