21315441211145 has 4 divisors (see below), whose sum is σ = 25578529453380. Its totient is φ = 17052352968912.

The previous prime is 21315441211123. The next prime is 21315441211193. The reversal of 21315441211145 is 54111214451312.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 14148212710921 + 7167228500224 = 3761411^2 + 2677168^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21315441211145 is a prime.

It is a super-2 number, since 2×21315441211145² (a number of 27 digits) contains 22 as substring.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2131544121110 + ... + 2131544121119.

It is an arithmetic number, because the mean of its divisors is an integer number (6394632363345).

Almost surely, 2^{21315441211145} is an apocalyptic number.

It is an amenable number.

21315441211145 is a deficient number, since it is larger than the sum of its proper divisors (4263088242235).

21315441211145 is an equidigital number, since it uses as much as digits as its factorization.

21315441211145 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4263088242234.

The product of its digits is 19200, while the sum is 35.

Adding to 21315441211145 its reverse (54111214451312), we get a palindrome (75426655662457).

The spelling of 21315441211145 in words is "twenty-one trillion, three hundred fifteen billion, four hundred forty-one million, two hundred eleven thousand, one hundred forty-five".