21155144131105 has 8 divisors (see below), whose sum is σ = 25387752483432. Its totient is φ = 16923062287488.

The previous prime is 21155144131087. The next prime is 21155144131127. The reversal of 21155144131105 is 50113144155112.

It can be written as a sum of positive squares in 4 ways, for example, as 3328449955216 + 17826694175889 = 1824404^2 + 4222167^2 .

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 21155144131105 - 2¹³ = 21155144122913 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 131538774 + ... + 131699503.

It is an arithmetic number, because the mean of its divisors is an integer number (3173469060429).

Almost surely, 2^{21155144131105} is an apocalyptic number.

It is an amenable number.

21155144131105 is a deficient number, since it is larger than the sum of its proper divisors (4232608352327).

21155144131105 is a wasteful number, since it uses less digits than its factorization.

21155144131105 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 263254355.

The product of its (nonzero) digits is 12000, while the sum is 34.

Adding to 21155144131105 its reverse (50113144155112), we get a palindrome (71268288286217).

The spelling of 21155144131105 in words is "twenty-one trillion, one hundred fifty-five billion, one hundred forty-four million, one hundred thirty-one thousand, one hundred five".