21015310311045 has 40 divisors (see below), whose sum is σ = 38187942930456. Its totient is φ = 11054628969984.

The previous prime is 21015310311031. The next prime is 21015310311049. The reversal of 21015310311045 is 54011301351012.

21015310311045 is a `hidden beast` number, since 2 + 10 + 1 + 531 + 0 + 3 + 110 + 4 + 5 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 7155229105476 + 13860081205569 = 2674926^2 + 3722913^2 .

It is not a de Polignac number, because 21015310311045 - 2⁸ = 21015310310789 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21015310311049) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 355379032 + ... + 355438161.

Almost surely, 2^{21015310311045} is an apocalyptic number.

It is an amenable number.

21015310311045 is a deficient number, since it is larger than the sum of its proper divisors (17172632619411).

21015310311045 is an equidigital number, since it uses as much as digits as its factorization.

21015310311045 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 710817283 (or 710817274 counting only the distinct ones).

The product of its (nonzero) digits is 1800, while the sum is 27.

Adding to 21015310311045 its reverse (54011301351012), we get a palindrome (75026611662057).

The spelling of 21015310311045 in words is "twenty-one trillion, fifteen billion, three hundred ten million, three hundred eleven thousand, forty-five".