21513051132243 has 16 divisors (see below), whose sum is σ = 31292112087936. Its totient is φ = 13038045578240.

The previous prime is 21513051132217. The next prime is 21513051132247. The reversal of 21513051132243 is 34223115031512.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 21513051132243 - 2⁶ = 21513051132179 is a prime.

It is a super-2 number, since 2×21513051132243² (a number of 27 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is not an unprimeable number, because it can be changed into a prime (21513051132247) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1544046 + ... + 6738707.

It is an arithmetic number, because the mean of its divisors is an integer number (1955757005496).

Almost surely, 2^{21513051132243} is an apocalyptic number.

21513051132243 is a deficient number, since it is larger than the sum of its proper divisors (9779060955693).

21513051132243 is a wasteful number, since it uses less digits than its factorization.

21513051132243 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8361474.

The product of its (nonzero) digits is 21600, while the sum is 33.

Adding to 21513051132243 its reverse (34223115031512), we get a palindrome (55736166163755).

The spelling of 21513051132243 in words is "twenty-one trillion, five hundred thirteen billion, fifty-one million, one hundred thirty-two thousand, two hundred forty-three".