21375123520513 has 32 divisors (see below), whose sum is σ = 25970175348480. Its totient is φ = 17174269347840.

The previous prime is 21375123520507. The next prime is 21375123520529. The reversal of 21375123520513 is 31502532157312.

It is a cyclic number.

It is not a de Polignac number, because 21375123520513 - 2²¹ = 21375121423361 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21375123520013) 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 31 ways as a sum of consecutive naturals, for example, 32476173 + ... + 33127813.

It is an arithmetic number, because the mean of its divisors is an integer number (811567979640).

Almost surely, 2^{21375123520513} is an apocalyptic number.

It is an amenable number.

21375123520513 is a deficient number, since it is larger than the sum of its proper divisors (4595051827967).

21375123520513 is a wasteful number, since it uses less digits than its factorization.

21375123520513 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 652777.

The product of its (nonzero) digits is 189000, while the sum is 40.

Adding to 21375123520513 its reverse (31502532157312), we get a palindrome (52877655677825).

The spelling of 21375123520513 in words is "twenty-one trillion, three hundred seventy-five billion, one hundred twenty-three million, five hundred twenty thousand, five hundred thirteen".