21131321224365 has 96 divisors (see below), whose sum is σ = 40577764032000. Its totient is φ = 10086604133760.

The previous prime is 21131321224357. The next prime is 21131321224411. The reversal of 21131321224365 is 56342212313112.

21131321224365 is a `hidden beast` number, since 2 + 1 + 1 + 3 + 1 + 3 + 212 + 2 + 436 + 5 = 666.

It is not a de Polignac number, because 21131321224365 - 2³ = 21131321224357 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 56159826 + ... + 56534844.

It is an arithmetic number, because the mean of its divisors is an integer number (422685042000).

Almost surely, 2^{21131321224365} is an apocalyptic number.

It is an amenable number.

21131321224365 is a deficient number, since it is larger than the sum of its proper divisors (19446442807635).

21131321224365 is a wasteful number, since it uses less digits than its factorization.

21131321224365 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 376807 (or 376804 counting only the distinct ones).

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

Adding to 21131321224365 its reverse (56342212313112), we get a palindrome (77473533537477).

The spelling of 21131321224365 in words is "twenty-one trillion, one hundred thirty-one billion, three hundred twenty-one million, two hundred twenty-four thousand, three hundred sixty-five".