21145343431311 has 144 divisors (see below), whose sum is σ = 34485643352160. Its totient is φ = 12470992934400.

The previous prime is 21145343431283. The next prime is 21145343431321. The reversal of 21145343431311 is 11313434354112.

21145343431311 is a `hidden beast` number, since 2 + 1 + 145 + 343 + 43 + 131 + 1 = 666.

It is not a de Polignac number, because 21145343431311 - 2²⁵ = 21145309876879 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21145343431321) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 5971572201 + ... + 5971575741.

It is an arithmetic number, because the mean of its divisors is an integer number (239483634390).

Almost surely, 2^{21145343431311} is an apocalyptic number.

21145343431311 is a deficient number, since it is larger than the sum of its proper divisors (13340299920849).

21145343431311 is a wasteful number, since it uses less digits than its factorization.

21145343431311 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4438 (or 4424 counting only the distinct ones).

The product of its digits is 51840, while the sum is 36.

Adding to 21145343431311 its reverse (11313434354112), we get a palindrome (32458777785423).

The spelling of 21145343431311 in words is "twenty-one trillion, one hundred forty-five billion, three hundred forty-three million, four hundred thirty-one thousand, three hundred eleven".