21155153513105 has 8 divisors (see below), whose sum is σ = 25926315795072. Its totient is φ = 16564035090928.

The previous prime is 21155153513101. The next prime is 21155153513107. The reversal of 21155153513105 is 50131535155112.

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 21155153513105 - 2² = 21155153513101 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21155153513101) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 45010964687 + ... + 45010965156.

It is an arithmetic number, because the mean of its divisors is an integer number (3240789474384).

Almost surely, 2^{21155153513105} is an apocalyptic number.

It is an amenable number.

21155153513105 is a deficient number, since it is larger than the sum of its proper divisors (4771162281967).

21155153513105 is an equidigital number, since it uses as much as digits as its factorization.

21155153513105 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 90021929895.

The product of its (nonzero) digits is 56250, while the sum is 38.

Adding to 21155153513105 its reverse (50131535155112), we get a palindrome (71286688668217).

The spelling of 21155153513105 in words is "twenty-one trillion, one hundred fifty-five billion, one hundred fifty-three million, five hundred thirteen thousand, one hundred five".